Byzantine navy

The Byzantine navy was the naval force of the Byzantine Empire. It started as the sea force of the old Roman Empire but became much more important for protecting the Byzantine state. While Roman fleets mostly patrolled the seas, control of the water was essential for the survival of the Byzantine Empire, which many call a "maritime empire."

In the 5th century, the Vandals were the first big threat to Roman control of the Mediterranean Sea. This changed during the wars of Justinian I in the 6th century. Around this time, the Byzantines created a permanent fleet and used a new type of ship called the dromon. As new threats arose, like the early Muslim conquests in the 7th century, the Byzantine navy became crucial. It defended the empire’s lands around the Mediterranean and protected the capital, Constantinople, from attacks. One of their famous secrets was "Greek fire," a special weapon that helped them win many battles.

At first, the main fleet that protected the coasts and Constantinople was called the Karabisianoi. Over time, this fleet was split into smaller regional groups, but a central fleet remained in Constantinople. By the late 8th century, the Byzantine navy was the strongest sea power in the Mediterranean. However, during the 11th century, the navy began to weaken. The empire had to rely on fleets from places like Venice and Genoa, which caused problems for its economy and independence. Even after some recovery, the navy continued to decline. By the mid-14th century, it had shrunk greatly, and control of the Aegean Sea passed to other navies. The small Byzantine fleet still operated until the fall of Constantinople to the Ottoman Empire in 1453.

Operational history

Early period

Civil wars and barbarian invasions: the 4th and 5th centuries

The Byzantine navy, like the Eastern Roman or Byzantine Empire itself, continued the systems of the Roman Empire. After the Battle of Actium in 31 BC, in the absence of any external threat in the Mediterranean, the Roman navy performed mostly policing and escort duties. Massive sea battles, like those fought centuries before in the Punic Wars (264 to 146 BC), no longer occurred, and the Roman fleets comprised relatively small vessels, best suited to their new tasks. By the early 4th century AD, the permanent Roman fleets had dwindled, so that when the fleets of the rival emperors Constantine the Great and Licinius clashed in 324 AD, they were composed to a great extent of newly built or -commandeered ships from the port cities of the Eastern Mediterranean. The civil wars of the 4th and early 5th centuries, however, did spur a revival of naval activity, with fleets mostly employed to transport armies. Considerable naval forces continued to be employed in the Western Mediterranean throughout the first quarter of the fifth century, especially from North Africa, but Rome's mastery of the Mediterranean was challenged when Africa was overrun by the Vandals (429 to 442).

The new Vandalic Kingdom of Carthage, under the capable Geiseric (r. 428–477), immediately launched raids against the coasts of Italy and Greece, even sacking and plundering Rome in 455. The Vandal raids continued unabated over the next two decades, despite repeated Roman attempts to defeat them. The Western Empire was impotent, its navy having dwindled to almost nothing, but the eastern emperors could still call upon the resources and naval expertise of the eastern Mediterranean. A first Eastern expedition in 448, however, went no further than Sicily, and in 460, the Vandals attacked and destroyed a Western Roman invasion fleet at Cartagena in Spain. Finally, in 468, a huge Eastern expedition assembled under Basiliscus, reputedly numbering 1,113 ships and 100,000 men, but it failed disastrously. About 600 ships were lost to fire ships, and the financial cost of 130,000 pounds of gold and 700,000 pounds of silver nearly bankrupted the Empire. This forced the Romans to come to terms with Geiseric and to sign a peace treaty. After Geiseric's death in 477, however, the Vandal threat receded.

Sixth century – Justinian restores Roman control over the Mediterranean

The 6th century marked the rebirth of Roman naval power. In 508, as antagonism with the Ostrogothic Kingdom of Theodoric flared up, the Emperor Anastasius I (r. 491–518) is reported to have sent a fleet of 100 warships to raid the coasts of Italy. In 513, the general Vitalian revolted against Anastasius. The rebels assembled a fleet of 200 ships which, despite some initial successes, were destroyed by admiral Marinus, who employed a sulphur-based incendiary substance to defeat them.

In 533, taking advantage of the absence of the Vandal fleet, sent to suppress a revolt in Sardinia, an army of 15,000 under Belisarius was transported to Africa by an invasion fleet of 92 dromons and 500 transports, beginning the Vandalic War, the first of the wars of the reconquest of Emperor Justinian I (r. 527–565). These were largely amphibious operations, made possible by the control of the Mediterranean waterways, and the fleet played a vital role in carrying supplies and reinforcements to the widely dispersed Byzantine expeditionary forces and garrisons. This fact was not lost on the Byzantines' enemies. Already in the 520s, Theodoric had planned to build a massive fleet directed against the Byzantines and the Vandals, but his death in 526 limited the extent to which these plans were realized. In 535, the Gothic War began with a double-pronged Byzantine offensive, with a fleet again carrying Belisarius' army to Sicily and then Italy, and another army invading Dalmatia. Byzantine control of the sea was of great strategic importance, allowing the smaller Byzantine army to successfully occupy the peninsula by 540.

In 541 however, the new Ostrogoth king, Totila, created a fleet of 400 warships with which to deny the seas around Italy to the Empire. Two Byzantine fleets were destroyed near Naples in 542, and in 546, Belisarius personally commanded 200 ships against the Gothic fleet that blockaded the mouths of the Tiber, in an unsuccessful effort to relieve Rome. In 550, Totila invaded Sicily, and over the next year, his 300-ship fleet captured Sardinia and Corsica, and raided Corfu and the coast of Epirus. However, a defeat in a sea battle off Sena Gallica marked the beginning of the final Imperial ascendancy. With the final conquest of Italy and southern Spain under Justinian, the Mediterranean once again became a "Roman lake".

Despite the subsequent loss of much of Italy to the Lombards, the Byzantines maintained control of the seas around the peninsula. As the Lombards rarely ventured to sea, the Byzantines were able to retain several coastal strips of Italian territory for centuries. The only major naval action of the next 80 years occurred during the siege of Constantinople by the Sassanid Persians, Avars and Slavs in 626. During that siege, the Slavs' fleet of monoxyla was intercepted by the Byzantine fleet and destroyed, denying the Persian army passage across the Bosporus and eventually forcing the Avars to retreat.

Struggle against the Arabs

Emergence of the Arab naval threat

Further informationon this period: Byzantine Empire under the Heraclian dynasty

During the 640s, the Muslim conquest of Syria and Egypt created a new threat to Byzantium. Not only did the Arabs conquer significant recruiting and revenue-producing areas, but, after the utility of a strong navy was demonstrated by the short-lived Byzantine recapture of Alexandria in 644, they took to creating a navy of their own. In this effort the new Muslim elite, which came from the inland-oriented northern part of the Arabian peninsula, largely relied on the resources and manpower of the conquered Levant (especially the Copts of Egypt), which until a few years previously had provided ships and crews for the Byzantines. There is, however, evidence that in the new naval bases in Palestine shipwrights from Persia and Iraq were also employed. The lack of illustrations earlier than the 14th century means that nothing is known about the specifics of the early Muslim warships, although it is usually assumed that their naval efforts drew upon the existing Mediterranean maritime tradition. Given a largely shared nautical nomenclature, and the centuries-long interaction between the two cultures, Byzantine and Arab ships shared many similarities. This similarity also extended to tactics and general fleet organization; translations of Byzantine military manuals were available to the Arab admirals.

"At that time Kallinikos, an artificer from Heliopolis, fled to the Romans. He had devised a sea fire which ignited the Arab ships and burned them with all hands. Thus it was that the Romans returned with victory and discovered the sea fire."

— Chronicle of Theophanes the Confessor, Annus Mundi 6165.

After seizing Cyprus in 649 and raiding Rhodes, Crete and Sicily, the young Arab navy decisively defeated the Byzantines under the personal command of Emperor Constans II (641–668) in the Battle of the Masts of 655. This catastrophic Byzantine defeat opened up the Mediterranean to the Arabs and began a centuries-long series of naval conflicts over the control of the Mediterranean waterways. From the reign of Muawiyah I (661–680), raids intensified, as preparations were made for a great assault on Constantinople itself. In the long first Arab siege of Constantinople, the Byzantine fleet proved instrumental to the survival of the Empire: the Arab fleets were defeated through the use of its newly developed secret weapon, known as "Greek fire". The Muslim advance in Asia Minor and the Aegean was halted, and an agreement to a thirty-year truce concluded soon after.

In the 680s, Justinian II (r. 685–695, 705–711) paid attention to the needs of the navy, strengthening it by the resettlement of over 18,500 Mardaites along the southern coasts of the Empire, where they were employed as marines and rowers. Nevertheless, the Arab naval threat intensified as they gradually took control of North Africa in the 680s and 690s. The last Byzantine stronghold, Carthage, fell in 698, although a Byzantine naval expedition managed to briefly retake it. The Arab governor Musa bin Nusair built a new city and naval base at Tunis, and 1,000 Coptic shipwrights were brought to construct a new fleet, which would challenge Byzantine control of the western Mediterranean. Thus, from the early 8th century on, Muslim raids unfolded unceasingly against Byzantine holdings in the Western Mediterranean, especially Sicily. In addition, the new fleet would allow the Muslims to complete their conquest of the Maghreb and to successfully invade and capture most of the Visigoth-controlled Iberian Peninsula.

Byzantine counter-offensive

Further informationon this period: Byzantine Empire under the Isaurian dynasty

The Byzantines were unable to respond effectively to the Muslim advance in Africa because the two decades between 695 and 715 were a period of great domestic turmoil. They did react with raids of their own in the East, such as the one in 709 against Egypt which captured the local admiral, but they also were aware of a coming onslaught: as Caliph al-Walid I (r. 705–715) readied his forces for a renewed assault against Constantinople, Emperor Anastasios II (r. 713–715) prepared the capital, and mounted an unsuccessful pre-emptive strike against the Muslim naval preparations. Anastasios was soon overthrown by Theodosius III (r. 715–717), who in turn was replaced, just as the Muslim army was advancing through Anatolia, by Leo III the Isaurian (r. 717–741). It was Leo III who faced the second and final Arab siege of Constantinople. The use of Greek fire, which devastated the Arab fleet, was again instrumental in the Byzantine victory, while a harsh winter and Bulgar attacks further sapped the besiegers' strength.

In the aftermath of the siege, the retreating remains of the Arab fleet were decimated in a storm, and Byzantine forces launched a counter-offensive, with a fleet sacking Laodicea and an army driving the Arabs from Asia Minor. For the next three decades, naval warfare featured constant raids from both sides, with the Byzantines launching repeated attacks against the Muslim naval bases in Syria (Laodicea), and Egypt (Damietta and Tinnis). In 727, a revolt of the provincial thematic fleets, largely motivated by resentment against the Emperor's iconoclasm, was put down by the imperial fleet through the use of Greek fire. Despite the losses this entailed, some 390 warships were reportedly sent to attack Damietta in 739, and in 746 the Byzantines decisively defeated the Alexandrian fleet at Keramaia in Cyprus, breaking the naval power of the Umayyad Caliphate.

The Byzantines followed this up with the destruction of the North African flotillas and coupled their successes at sea with severe trading limitations imposed on Muslim traders. Given the Empire's new ability to control the waterways, this strangled Muslim maritime trade. With the collapse of the Umayyad state shortly thereafter and the increasing fragmentation of the Muslim world, the Byzantine navy was left as the sole organized naval force in the Mediterranean. Thus, during the latter half of the 8th century, the Byzantines enjoyed a second period of complete naval superiority. It is no coincidence that in the many Islamic apocalyptic texts composed and transmitted during the first and second Islamic centuries, the End Times are preceded by a seaborne Byzantine invasion. Many traditions from the period stress that manning the guard posts (ribat) on the coasts of Syria is tantamount to partaking in the jihad, and authorities like Abu Hurayrah were cited as considering one day of ribat more pious an act than a night of prayer in the Kaaba.

These successes enabled Emperor Constantine V (r. 741–775) to shift the fleet from the Mediterranean to the Black Sea during his campaigns against the Bulgars in the 760s. In 763, a fleet of 800 ships carrying 9,600 cavalries and some infantry sailed to Anchialus, where he scored a significant victory, but in 766, a second fleet, allegedly of 2,600 ships, again bound for Anchialus, sank en route. At the same time, however, the Isaurian emperors undermined Byzantium's naval strength: with the Arab threat gone for the moment, and with the largely iconodule naval themes staunchly opposed to their iconoclastic policies, the emperors reduced the navy's size and downgraded the naval themes.

Renewed Muslim ascendancy

The Byzantine naval predominance lasted until the early 9th century when a succession of disasters at the hands of the resurgent Muslim fleets spelled its end and inaugurated an era that would represent the zenith of Muslim ascendancy. Already in 790, the Byzantines suffered a major defeat in the Gulf of Antalya, and raids against Cyprus and Crete recommenced during the reign of Harun al-Rashid (786–809). Around the Mediterranean, new powers were rising, foremost amongst them the Carolingian Empire, while in 803, the Pax Nicephori recognized the de facto independence of Byzantine Venice, which was further entrenched by the repulsion of a Byzantine attack in 809. At the same time, in Ifriqiya, the new Aghlabid dynasty was established, which immediately engaged in raids throughout the central Mediterranean.

The Byzantines, on the other hand, were weakened by a series of catastrophic defeats against the Bulgars, followed in 820 by the Revolt of Thomas the Slav, which attracted the support of a large part of the Byzantine armed forces, including the thematic fleets. Despite its suppression, the revolt had severely depleted the Empire's defences. As a result, Crete fell between 824 and 827 to a band of Andalusian exiles. Three successive Byzantine recovery attempts failed over the next few years, and the island became a base for Muslim piratical activity in the Aegean, radically upsetting the balance of power in the region. Despite some Byzantine successes over the Cretan corsairs, and the razing of Damietta by a Byzantine fleet of 85 ships in 853, Arab naval power in the Levant was steadily reviving under Abbasid rule. Further Byzantine attempts to recover Crete, in 843 and 866, were complete failures.

"During that time [...] the Muslims gained control over the whole Mediterranean. Their power and domination over it was vast. The Christian nations could do nothing against the Muslim fleets, anywhere in the Mediterranean. All the time, the Muslims rode its wave for conquest."

— Ibn Khaldun, Muqaddimah, III.32

The situation was even worse in the West. A critical blow was inflicted on the Empire in 827, as the Aghlabids began the slow conquest of Sicily, aided by the defection of the Byzantine commander Euphemios and the island's thematic fleet. In 838, the Muslims crossed over into Italy, taking Taranto and Brindisi, followed soon by Bari. Venetian operations against them were unsuccessful, and throughout the 840s, the Arabs were freely raiding Italy and the Adriatic, even attacking Rome in 846. Attacks by the Lombards and Lothair I failed to dislodge the Muslims from Italy, while two large-scale Byzantine attempts to recover Sicily were heavily defeated in 840 and 859. By 850, the Muslim fleets, together with large numbers of independent ghazi raiders, had emerged as the major power of the Mediterranean, putting the Byzantines and the Christians in general on the defensive.

The same period, when a battered Byzantium defended itself against enemies on all fronts, also saw the emergence of a new, unexpected threat: the Rus' made their first appearance in Byzantine history with a raid against Paphlagonia in the 830s, followed by a major expedition in 860.

Byzantine Reconquest: the era of the Macedonian dynasty

Further informationon this period: Byzantine Empire under the Macedonian dynasty

During the course of the later 9th and the 10th century, as the Caliphate fractured into smaller states and Arab power became weakened, the Byzantines launched a series of successful campaigns against them. This "Byzantine Reconquest" was overseen by the able sovereigns of the Macedonian dynasty (867–1056), and marked the noontide of the Byzantine state.

Reign of Basil I

The ascension of Emperor Basil I (867–886) heralded this revival, as he embarked on an aggressive foreign policy. Continuing the policies of his predecessor, Michael III (842–867), he showed great care to the fleet, and as a result, successive victories followed. In 868, a fleet under the droungarios tou ploïmou Niketas Ooryphas relieved Ragusa from an Arab siege and re-established Byzantine presence in the area. A few years later, he twice heavily defeated the Cretan pirates at Kardia and in the Corinthian Gulf, temporarily securing the Aegean. Cyprus also was temporarily recovered and Bari occupied. At the same time, however, the Muslim presence in Cilicia was strengthened, and Tarsos became a major base for land and seaborne attacks against Byzantine territory, especially under the famed emir Yazaman al-Khadim (882–891), despite the heavy defeat of one of his raids before Euripos.

In the West, the Muslims continued to make steady advances, as the local Byzantine forces proved inadequate: the Empire was forced to rely on the aid of their nominal Italian subjects, and had to resort to the transfer of the eastern fleets to Italy to achieve any progress. Following the fall of Enna in 855, the Byzantines were confined to the eastern shore of Sicily, and under increasing pressure. A relief expedition in 868 achieved little. Syracuse was attacked again in 869, and in 870, Malta fell to the Aghlabids. Muslim corsairs raided the Adriatic, and although they were driven out of Apulia, in the early 880s they established bases along the western Italian coast, from where they would not be completely dislodged until 915. In 878, Syracuse, the main Byzantine stronghold in Sicily, was attacked again and fell, largely because the Imperial Fleet was occupied with transporting marble for the construction of the Nea Ekklesia, Basil's new church. In 880, Ooryphas' successor, the droungarios Nasar, scored a significant victory in a night battle over the Aghlabids who were raiding the Ionian Islands. He then proceeded to raid Sicily, carrying off much booty, before defeating another Muslim fleet off Punta Stilo. At the same time, another Byzantine squadron scored a significant victory at Naples. These successes allowed a short-lived Byzantine counter-offensive to develop in the West in the 870s and 880s under Nikephoros Phokas the Elder, expanding the Byzantine foothold in Apulia and Calabria and forming the theme of Longobardia, which would later evolve into the Catepanate of Italy. A heavy defeat off Milazzo in 888, however, signalled the virtual disappearance of major Byzantine naval activity in the seas around Italy for the next century.

Arab raids during the reign of Leo VI

Despite the successes under Basil, during the reign of his successor Leo VI the Wise (886–912), the Empire again faced serious threats. In the north, a war broke out against the Bulgarian Tsar Simeon, and a part of the Imperial Fleet was used in 895 to ferry an army of Magyars across the Danube to raid Bulgaria. The Bulgarian war produced several costly defeats, while at the same time the Arab naval threat reached new heights, with successive raids devastating the shores of Byzantium's naval heartland, the Aegean Sea. In 891 or 893, the Arab fleet sacked the island of Samos and took its strategos (military governor) prisoner, and in 898, the eunuch admiral Raghib carried off 3,000 Byzantine sailors of the Cibyrrhaeots as prisoners. These losses denuded Byzantine defences, opening the Aegean up to raids by the Syrian fleets. The first heavy blow came in 901, when the renegade Damian of Tarsus plundered Demetrias, while in the next year, Taormina, the Empire's last outpost in Sicily, fell to the Muslims. The greatest disaster, however, came in 904, when another renegade, Leo of Tripoli, raided the Aegean. His fleet penetrated even into the Dardanelles, before proceeding to sack the Empire's second city, Thessalonica, all while the Empire's fleet remained passive in the face of the Arabs' superior numbers. Furthermore, the Cretan corsairs' raids reached such intensity, that by the end of Leo's reign, most of the southern Aegean islands were either abandoned or forced to accept Muslim control and pay tribute to the pirates. It is no surprise that a defensive and cautious mindset was prevalent in Leo's contemporary instructions on naval warfare (Naumachica).

The most distinguished Byzantine admiral of the period was Himerios, the logothetes tou dromou. Appointed admiral in 904, he was unable to prevent the sack of Thessalonica, but he scored the first victory in 905 or 906, and in 910, he led a successful attack on Laodicea. The city was sacked and its hinterland plundered and ravaged without the loss of any ships. A year later, however, a huge expedition of 112 dromons and 75 pamphyloi with 43,000 men, that had sailed under Himerios against the Emirate of Crete, not only failed to recover the island, but on its return voyage, it was ambushed and comprehensively defeated by Leo of Tripoli off Chios (October 912).

The tide began to turn again after 920. Coincidentally, the same year witnessed the ascension of an admiral, Romanos Lekapenos (920–944), to the imperial throne, for the second (after Tiberios Apsimaros) and last time in the Empire's history. Finally, in 923, the decisive defeat of Leo of Tripoli off Lemnos, coupled with the death of Damian during a siege of a Byzantine fortress in the next year, marked the beginning of the Byzantine resurgence.

Recovery of Crete and the northern Levant

The Empire's growing might be displayed in 942, when Emperor Romanos I dispatched a squadron to the Tyrrhenian Sea. Using Greek fire, the squadron destroyed a fleet of Muslim corsairs from Fraxinetum. In 949, however, another expedition of about 100 ships, launched by Constantine VII (945–959) against the Emirate of Crete, ended in disaster, due to the incompetence of its commander, Constantine Gongyles. A renewed offensive in Italy in 951–952 was defeated by the Fatimids, but another expedition in 956 and the loss of an Ifriqiyan fleet in a storm in 958 temporarily stabilized the situation in the peninsula. In 962, the Fatimids launched an assault on the remaining Byzantine strongholds on Sicily; Taormina fell on Christmas Day 962 and Rometta was besieged. In response, a major Byzantine expedition was launched in 964 but ended in disaster. The Fatimids defeated the Byzantine army before Rametta and then annihilated the fleet at the Battle of the Straits, notably through the use of divers bearing incendiary devices. Both powers focusing their attention elsewhere, a truce was concluded between Byzantium and the Fatimids in 967, which curbed Byzantine naval activity in the West: the seas of Italy were left to the local Byzantine forces and the various Italian states until after 1025, when Byzantium again actively intervened in southern Italy and Sicily.

In the East, in 956 the strategos Basil Hexamilites inflicted a crushing defeat on the Tarsiot fleet, opening the way for another grand expedition to recover Crete. It was entrusted to Nikephoros Phokas, who in 960 set out with a fleet of 100 dromons, 200 chelandia, and 308 transports, carrying an overall force of 77,000 men, to subdue the island. Although the navy ultimately had a limited combat role in the campaign, it was essential for keeping the sea-lanes open after a disastrous attack into the interior of the island required supplies to be brought in by sea. The conquest of Crete removed the direct threat to the Aegean, Byzantium's naval heartland, while Phokas' subsequent operations led to the recovery of Cilicia (in 963), Cyprus (in 968), and the northern Syrian coast (in 969). These conquests removed the threat of the once mighty Muslim Syrian fleets, effectively re-establishing Byzantine dominance in the Eastern Mediterranean so that Nikephoros Phokas could boast to Liutprand of Cremona with the words "I alone command the sea". A few raids and naval clashes occurred as antagonism with the Fatimids mounted in the late 990s, but peaceful relations were restored soon after, and the Eastern Mediterranean remained relatively calm for several decades to come.

During the same period, the Byzantine fleet was active in the Black Sea as well: a Rus' fleet that was threatening Constantinople in 941 was destroyed by 15 hastily assembled old ships equipped with Greek fire, and the navy played an important role in the Rus'–Byzantine War of 970–971, when John I Tzimiskes (969–976) sent 300 ships to blockade the Kievan Rus' from retreating over the Danube.

Komnenian period

Further informationon this period: Byzantine Empire under the Komnenos dynasty

Decline during the 11th century

Throughout most of the 11th century, the Byzantine navy faced few challenges. The Muslim threat had receded, as their navies declined and relations between the Fatimids, especially, and the Empire were largely peaceful. The last Arab raid against imperial territory was recorded in 1035 in the Cyclades, and was defeated in the next year. Another Rus' attack in 1043 was beaten back with ease, and with the exception of a short-lived attempt to recover Sicily under George Maniakes, no major naval expeditions were undertaken either. Inevitably, this long period of peace and prosperity led to complacency and neglect of the military. Already in the reign of Basil II (976–1025), the defence of the Adriatic was entrusted to the Venetians. Under Constantine IX (1042–1055), both the army and navy were reduced as military service was increasingly commuted in favour of cash payments, resulting in an increased dependency upon foreign mercenaries. The large thematic fleets declined and were replaced by small squadrons subject to the local military commanders, geared more towards the suppression of piracy than towards confronting a major maritime foe.

By the last quarter of the 11th century, the Byzantine navy was a shadow of its former self, having declined through neglect, the incompetence of its officers, and lack of funds. Kekaumenos, writing in c. 1078, laments that "on the pretext of reasonable patrols, [the Byzantine ships] are doing nothing else but ferrying wheat, barley, pulse, cheese, wine, meat, olive oil, a great deal of money, and anything else" from the islands and coasts of the Aegean, while they "flee [the enemy] before they have even caught sight of them, and thus become an embarrassment to the Romans". By the time Kekaumenos wrote, new and powerful adversaries had risen. In the West, the Norman Kingdom of Sicily, which had expelled the Byzantines from Southern Italy and had conquered Sicily, was now casting its eye on the Byzantine Adriatic coasts and beyond. In the East, the disastrous Battle of Manzikert in 1071 had resulted in the loss of Asia Minor, the Empire's military and economic heartland, to the Seljuk Turks, who by 1081 had established their capital at Nicaea, barely a hundred miles south of Constantinople. Soon after, Turkish as well as Christian pirates appeared in the Aegean. The Byzantine thematic fleets, which once policed the seas, were by then so depleted by neglect and the successive civil wars that they were incapable of responding effectively.

Attempts at recovery under Alexios I and John II

At this point, the sorry state of the Byzantine fleet had dire consequences. The Norman invasion could not be forestalled, and their army seized Corfu, landed unopposed in Epirus and laid siege to Dyrrhachium, starting a decade of war which consumed the scant resources of the embattled Empire. The new emperor, Alexios I Komnenos (1081–1118), was forced to call upon the assistance of the Venetians, who in the 1070s had already asserted their control of the Adriatic and Dalmatia against the Normans. In 1082, in exchange for their help, he granted them major trading concessions. This treaty, and subsequent extensions of these privileges, practically rendered the Byzantines hostage to the Venetians (and later also the Genoese and the Pisans). Historian John Birkenmeier notes that:

Byzantium's lack of a navy [...] meant that Venice could regularly extort economic privileges, determine whether invaders, such as the Normans or Crusaders entered the Empire, and parry any Byzantine attempts to restrict Venetian commercial or naval activity.

In the clashes with the Normans through the 1080s, the only effective Byzantine naval force was a squadron commanded, and possibly maintained, by Michael Maurex, a veteran naval commander of previous decades. Together with the Venetians, he initially prevailed over the Norman fleet, but the joint fleet was caught off guard and defeated by the Normans off Corfu in 1084.

Alexios inevitably realized the importance of having his own fleet, and despite his preoccupation with land operations, he took steps to re-establish the navy's strength. His efforts bore some success, especially in countering the attempts by Turkish emirs like Tzachas of Smyrna to launch fleets in the Aegean. The fleet under John Doukas was subsequently used to suppress revolts in Crete and Cyprus. With the aid of the Crusaders, Alexios was able to regain the coasts of Western Anatolia and expand his influence eastwards: in 1104, a Byzantine squadron of 10 ships captured Laodicea and other coastal towns as far as Tripoli. By 1118, Alexios was able to pass on a small navy to his successor, John II Komnenos (1118–1143). Like his father, John II concentrated on the army and regular land-based campaigns, but he took care to maintain the navy's strength and provisioning system. In 1122, however, John refused to renew the trading privileges that Alexios had granted to the Venetians. In retaliation, the Venetians plundered several Byzantine islands, and, with the Byzantine fleet unable to confront them, John was forced to renew the treaty in 1125. Evidently, the Byzantine navy at this point was not sufficiently powerful for John to successfully confront Venice, especially since there were other pressing demands on the Empire's resources. Not long after this incident, John II, acting on the advice of his finance minister John of Poutza, is reported to have cut funding to the fleet and transferred it to the army, equipping ships on an ad hoc basis only.

Naval expeditions of Manuel I

The navy enjoyed a major comeback under the ambitious emperor Manuel I Komnenos (1143–1180), who used it extensively as a powerful tool of foreign policy in his relations with the Latin and Muslim states of the Eastern Mediterranean. During the early years of his reign, the Byzantine naval forces were still weak: in 1147, the fleet of Roger II of Sicily under George of Antioch was able to raid Corfu, the Ionian islands and into the Aegean almost unopposed. In the next year, with Venetian aid, an army accompanied by a very large fleet (allegedly 500 warships and 1,000 transports) was sent to recapture Corfu and the Ionian Islands from the Normans. In retaliation, a Norman fleet of 40 ships reached Constantinople itself, demonstrating in the Bosporus off the Great Palace and raiding its suburbs. On its return voyage however it was attacked and destroyed by a Byzantine or Venetian fleet.

In 1155, a Byzantine squadron of 10 ships in support of Norman rebel Robert III of Loritello arrived at Ancona, launching the last Byzantine bid to regain Southern Italy. Despite initial successes and reinforcements under megas doux Alexios Komnenos Bryennios, the expedition was ultimately defeated in 1156, and 4 Byzantine ships were captured. By 1169, the efforts of Manuel had evidently borne fruit, as a large and purely Byzantine fleet of about 150 galleys, 10-12 large transports and 60 horse transports under megas doux Andronikos Kontostephanos was sent to invade Egypt in cooperation with the ruler of the Crusader Kingdom of Jerusalem. The invasion failed, however, and the Byzantines lost half the fleet in a storm on the way back.

Following the Empire-wide seizure and imprisonment of all Venetians in March 1171, the Byzantine fleet was strong enough to deter an outright attack by the Venetians, who sailed to Chios and settled for negotiations. Manuel sent a fleet of 150 ships under Kontostephanos to confront them there and employed delaying tactics, until, weakened by disease, the Venetians began to withdraw and were pursued by Kontostephanos' fleet. It was a remarkable reversal of fortunes, compared with the humiliation of 1125. In 1177, another fleet of 70 galleys and 80 auxiliary ships under Kontostephanos, destined for Egypt, returned home after appearing off Acre, as Count Philip of Flanders and many important nobles of the Kingdom of Jerusalem refused to participate in the campaign. However, by the end of Manuel's reign, the strains of constant warfare on all fronts and the Emperor's various grandiose projects had become evident: the historian Niketas Choniates attributes the rise of piracy in the latter years of Manuel's reign to the diversion of the funds intended for the maintenance of the fleet for other needs of the imperial treasury.

Decline

Angelos dynasty and the Fourth Crusade

After the death of Manuel I and the subsequent demise of the Komnenian dynasty in 1185, the navy declined swiftly. The maintenance of galleys and the upkeep of proficient crews were very expensive, and neglect led to a rapid deterioration of the fleet. Already by 1182 the Byzantines had to pay Venetian mercenaries to crew some of their galleys, but in the 1180s, as the bulk of the Komnenian naval establishment persisted, expeditions of 70–100 ships are still recorded in contemporary sources. Thus Emperor Andronikos I Komnenos (1183–1185) could still gather 100 warships in 1185 to resist and later defeat a Norman fleet in the Sea of Marmara. However, the subsequent peace treaty included a clause that required the Normans to furnish a fleet for the Empire. This, together with a similar agreement made by Isaac II Angelos (1185–1195 and 1203–1204) with Venice the next year, in which the Republic would provide 40–100 galleys at six months' notice in exchange for favourable trading concessions, is a telling indication that the Byzantine government was aware of the inadequacy of its own naval establishment.

The period also saw the rise of piracy across the Eastern Mediterranean. The pirate activity was high in the Aegean, while pirate captains frequently offering themselves as mercenaries to one or the other of the region's powers, providing for the latter a quick and cheap way of raising a fleet for particular expeditions, without the costs of a standing navy. Thus a Byzantine fleet of 66 vessels sent by Isaac II to recapture Cyprus from Isaac Komnenos was destroyed by the pirate Margaritus of Brindisi, who was in the employ of the Normans of Sicily. The depredations of the pirates, especially the Genoese captain Kaphoures, described by Niketas Choniates and his brother, the Metropolitan of Athens Michael Choniates, finally forced the Angeloi to action. The fleet tax was once again levied from the coastal regions and a navy of 30 ships was equipped, which was entrusted to the Calabrian pirate Steiriones. Despite scoring a few early successes, Steiriones' fleet was destroyed in a surprise attack by Kaphoures off Sestos. A second fleet, augmented by Pisan vessels and again commanded by Steiriones, was finally able to defeat Kaphoures and end his raids.

At the same time, however, the then megas doux, Michael Stryphnos, was accused by Niketas Choniates of enriching himself by selling off the equipment of the imperial fleet, while by the early 13th century the authority of the central government had weakened to such an extent that various local potentates began seizing power in the provinces. The general atmosphere was one of lawlessness, which enabled men like Leo Sgouros in southern Greece and the imperial governor of Samos, Pegonites, to use their ships for their own purposes, launching raids of their own. Even Emperor Alexios III Angelos (1195–1203) is said to have licensed one of his commanders, Constantine Phrangopoulos, to launch pirate raids against commerce in the Black Sea.

The Byzantine state and its fleet were thus in no state to resist the naval might of Venice, which supported the Fourth Crusade. When Alexios III and Stryphnos were alerted to the fact that the Crusade was sailing for Constantinople, only 20 "wretched and decayed" vessels could be found, according to Niketas Choniates. During the first Crusader siege of the city in 1203, the attempts of the Byzantine ships to oppose the Crusader fleet from entering the Golden Horn were repulsed, and the Byzantine attempt to employ fireships failed due to the Venetians' skill at handling their ships.

Nicaea and the Palaiologan period

After the capture of Constantinople by the Fourth Crusade in 1204, the Byzantine Empire was partitioned between the Crusaders, while three Greek successor states were set up, the Despotate of Epirus, the Empire of Trebizond, and the Empire of Nicaea, each claiming the Byzantine imperial title. The former did not maintain a fleet, the Trapezuntine navy was minuscule and mostly used for patrols and transporting troops, while the Nicaeans initially followed a policy of consolidation and used their fleet for coastal defence. Under John III Vatatzes (1222–1254), a more energetic foreign policy was pursued, and in 1225, the Nicaean fleet was able to occupy the islands of Lesbos, Chios, Samos, and Icaria. It was, however, no match for the Venetians: attempting to blockade Constantinople in 1235, the Nicaean navy was defeated by a far smaller Venetian force, and in another similar attempt in 1241, the Nicaeans were again routed. Nicaean efforts during the 1230s to support a local rebellion in Crete against Venice were also only partially successful, with the last Nicaean troops being forced to leave the island in 1236. Aware of the weakness of his navy, in March 1261 the Emperor Michael VIII Palaiologos (1259–1282) concluded the Treaty of Nymphaeum with the Genoese, securing their aid against Venice at sea, in return for commercial privileges.

Following the recapture of Constantinople a few months later however, Michael VIII was able to focus his attention on building up his own fleet. In the early 1260s, the Byzantine navy was still weak and depended still greatly on Genoese aid. Even so, the allies were not able to stand up to Venice in a direct confrontation, as evidenced by the defeat of a combined Byzantine–Genoese fleet of 48 ships by a much smaller Venetian fleet in 1263. Taking advantage of the Italians' preoccupation with the ongoing Venetian–Genoese war, by 1270 Michael's efforts had produced a strong navy of 80 ships, with several Latin privateers sailing under imperial colours. In the same year, a fleet of 24 galleys besieged the town of Oreos in Negroponte (Euboea), and defeated a Latin fleet of 20 galleys. This marked the first successful independent Byzantine naval operation and the beginning of an organized naval campaign in the Aegean that would continue throughout the 1270s and would result in the recapture, albeit briefly, of many islands from the Latins.

This revival did not last long. Following the death of Charles of Anjou in 1285 and the end of the threat of an invasion from Italy, Michael's successor Andronikos II Palaiologos (1282–1328) assumed that, by relying on the naval strength of his Genoese allies, he could do without the maintenance of a fleet, whose particularly heavy expenditure the increasingly cash-strapped treasury could no longer afford. At the same time, Andronikos was less concerned with the West and more with affairs in Asia Minor and his—eventually futile—attempt to stop the Turkish advance there, a policy where the fleet lacked a role. Consequently, the entire fleet was disbanded, its crews dismissed and the ships are broken up or left to rot. The results were quick to follow: during Andronikos' long reign, the Turks gradually took permanent possession of the Aegean coasts of Anatolia, with the Empire unable to reverse the situation, while the Venetian fleet was able to attack Constantinople and raid its suburbs at will during the 1296–1302 war.

Andronikos' decision aroused considerable opposition and criticism from contemporary scholars and officials almost from the outset, and historians like Pachymeres and Nikephoros Gregoras dwell long on the disastrous long-term effects of this short-sighted decision: piracy flourished, often augmented by the crews of the disbanded fleet who took service under Turkish and Latin masters, Constantinople was rendered defenceless towards the Italian maritime powers, and more and more Aegean islands fell under foreign rule—including Chios to the Genoese Benedetto Zaccaria, Rhodes and the Dodecanese to the Hospitallers, Lesbos and other islands to the Gattilusi. As Gregoras commented, "if [the Byzantines] had remained masters of the seas, as they had been, then the Latins would not have grown so arrogant [...], nor would the Turks ever have gazed upon the sands of the [Aegean] sea, [...] nor would we have to pay to everyone tribute every year." After 1305, bowing to popular pressure and the need to contain the Catalan Company, the Emperor belatedly tried to rebuild the navy of 20 vessels, but although a few ships were built and a small fleet appears to have been active over the next couple of years, it eventually was disbanded again.

In the 14th century, recurrent civil wars, attacks from Bulgaria and Serbia in the Balkans and the devastation caused by ever-increasing Turkish raids hastened the collapse of the Byzantine state, which would culminate in its final fall to the Ottoman Turks in 1453. Several emperors after Andronikos II also tried to re-build a fleet, especially in order to secure the security and hence the independence of Constantinople itself from the interference of the Italian maritime powers, but their efforts produced only short-term results.

Thus Andronikos III Palaiologos (1328–1341), immediately after his accession, with the help of contributions from various magnates, assembled a large fleet of reportedly 105 vessels. This he personally led in the last major foray of a Byzantine navy in the Aegean, recovering Chios and Phocaea from the Genoese and forcing various smaller Latin and Turkish principalities to come to terms with him. His campaigns against the Ottomans in Bithynia were failures, however, and soon the Ottomans had established their first naval base at Trigleia on the Sea of Marmara, from where they raided the coasts of Thrace. To defend against this new threat, towards the end of Andronikos III's reign a fleet of some 70 ships was built at Constantinople to oppose the Turkish raids, and headed by the megas doux, Alexios Apokaukos. This fleet was very active during the civil war of 1341–1347, in which its commander played a prominent role. Following the civil war, Emperor John VI Kantakouzenos (1347–1354) tried to restore the navy and merchant fleet, as a means of both reducing the Empire's economic dependency on the Genoese colony of Galata, which controlled the trade passing through Constantinople, and of securing the control of the Dardanelles against passage by the Turks. To that end, he enlisted the aid of the Venetians, but in March 1349, his newly built fleet of nine warships and about 100 smaller vessels were caught in a storm off the southern shore of Constantinople. The inexperienced crews panicked, and the ships were either sunk or captured by the Genoese. Undeterred, Kantakouzenos launched another effort at building a fleet, which allowed him to re-establish Byzantine authority over Thessalonica and some coastal cities and islands. A core of this fleet was maintained at Constantinople, and although Byzantine ships remained active in the Aegean, and scored some successes over Turkish pirates, they were never able to stop their activities, let alone challenge the Italian navies for supremacy at sea. Lack of funds condemned the fleet to a mere handful of vessels maintained at Constantinople. It is characteristic that in his 1418 pamphlet to the despotes Theodore II Palaiologos, the scholar Gemistos Plethon advises against the maintenance of a navy, on the grounds that resources were insufficient to adequately maintain both it and an effective army.

Henceforth, the impoverished Byzantine state became a pawn of the great powers of the day, trying to survive by exploiting their rivalries. Thus in 1351, Kantakouzenos was induced to side with Venice in its war with Genoa, but the subsequent battle ended in a carnage, and the Venetian admirals preferred to not risk another battle. Abandoned by his allies, Kantakouzenos was forced to sign an unfavourable peace. During the brief usurpation of John VII in 1390, Manuel II (1391–1425) was able to gather only five galleys and four smaller vessels (including some from the Hospitallers of Rhodes) to recapture Constantinople and rescue his father John V. Six years later, Manuel promised to arm ten ships to assist the Crusade of Nicopolis; twenty years later, he personally commanded 4 galleys and 2 other vessels carrying some infantry and cavalry, and saved the island of Thasos from an invasion. Byzantine ships were active throughout the Ottoman Interregnum, when Byzantium sided with various rival Ottoman princes in turn. Manuel used his ships to ferry the rival pretenders and their forces across the Straits. With Genoese assistance, Manuel's fleet was also able to muster a fleet of eight galleys and capture Gallipoli in May 1410, albeit for a brief time; and in August 1911, the Byzantine fleet was instrumental in the failure of a siege of Constantinople by the Ottoman prince Musa Çelebi, when it defeated Musa's attempt to blockade the city by sea as well. Likewise, in 1421, 10 Byzantine warships were engaged in support of the Ottoman pretender Mustafa against Sultan Murad II.

The last recorded Byzantine naval victory occurred in 1427 in a battle off the Echinades Islands, when the Emperor John VIII Palaiologos (1425–1448) defeated the superior fleet of Carlo I Tocco, Count of Cephalonia and Despot of Epirus, forcing him to relinquish all his holdings in the Morea to the Byzantines. The last appearance of the Byzantine navy was in the final Ottoman siege of 1453, when a mixed fleet of Byzantine, Genoese and Venetian ships (varying numbers are provided by the sources, ranging from 10 to 39 vessels) defended Constantinople against the Ottoman fleet. During the siege, on 20 April 1453, the last naval engagement in Byzantine history took place when three Genoese galleys escorting a Byzantine transport fought their way through the huge Ottoman blockade fleet and into the Golden Horn.

Return only the adapted Markdown section. No explanation, no preamble.

Organization

Early period (4th – mid-7th centuries)

Very little is known about how the Roman navy was organized in the late 300s to mid-600s. Earlier ideas that the navy almost disappeared by the 300s have changed, and we now understand it transformed into a smaller force focused on rivers and coastal areas, working closely with the army.

Under Emperor Diocletian, the navy grew from about 46,000 sailors to 64,000, its highest number in this period. The Danube Fleet was well-known, and writers like Vegetius mentioned its activities. In the West, some river fleets existed, but the main navy had mostly disappeared. In the East, fleets in Syria and Alexandria were still around in the year 400, and there was a fleet in Constantinople, though its size is unknown.

In the 400s, fleets were often put together for specific missions and then broken up again. The first permanent Byzantine fleet started in the early 500s during a revolt led by Vitalian. This fleet was kept and grew into a professional force under Emperor Justinian I and his successors. By the late 500s, the navy was small, with a few small groups on the Danube and two main fleets in Ravenna and Constantinople. Other important places like Alexandria, Carthage, Septem (Ceuta), Cherson in Crimea, and Aelana (Eilat) also had troops and ships. These areas had strong naval traditions, making it easier to build up fleets quickly when needed.

Middle period (late 7th century – 1070s)

Fleet organization

In response to Arab attacks in the 600s, the Byzantine Empire reorganized its military and administrative systems. The Empire was divided into regions called themes, each with its own local forces led by a strategos. Later, larger themes were split, and a central army called the tagmata was created in Constantinople.

A similar change happened in the navy. In the late 600s, a new fleet called the Karabisianoi was formed. Its exact start date is unclear, but it was responsible for the southern coast of Asia Minor, the Aegean islands, and southern Greece. It was led by a strategos and had its headquarters possibly at Samos.

The Karabisianoi were replaced in the early 700s by a new system with three parts: a central fleet in Constantinople, a few large regional naval commands, and many smaller local squadrons for defense. Unlike the old Roman navy, the regional fleets in Byzantium were strong and important.

The Imperial Fleet

The navy in Constantinople played a key role in defending against Arab attacks. The exact start date of the Imperial Fleet as a separate group is not clear. Some historians think it existed as early as the 600s under the strategos of the Karabisianoi, while others believe it started in the early 800s. From then on, the Imperial Fleet was the main reserve and core of many expeditionary fleets.

Maritime themes

The first maritime theme was the Theme of the Cibyrrhaeots, created from the Karabisianoi fleet. It was responsible for the southern coasts of Asia Minor and was led by a strategos based in Attaleia. It included leaders like the katepano of the Mardaites and droungarioi in Attaleia and Kos. This fleet was important for centuries until the threat from Arabs decreased. It was last mentioned in 1043 and then became just a civilian area.

The Cibyrrhaeots were supported by two independent naval commands in the Aegean, each led by a droungarios. These were later turned into full maritime themes: the Theme of the Aegean Sea around 843 and the Theme of Samos in the late 800s, which included the Ionian coast and had its capital in Smyrna.

Local squadrons

Some land themes also had their own squadrons, usually led by a tourmarches. These squadrons were permanent with professional crews and were used for local defense and police work. They included:

• The Theme of Hellas, founded around 686–689 by Justinian II, included southern Greece with its capital in Corinth. It had its own fleet and was later split into the Theme of the Peloponnese and the new Theme of Hellas, covering Central Greece and Thessaly, which also kept smaller fleets.
• The Theme of Sicily was responsible for Sicily and parts of south-western Italy (Calabria). Once strong, it weakened by the late 800s and disappeared after losing Taormina in 902.
• The Theme of Cephallenia controlled the Ionian Islands and was created in the mid- to late 700s to protect communications with Italy and defend the Ionian Sea from Arab attacks. New lands in Apulia were added in the 870s before becoming a separate theme of Longobardia around 910.
• The Theme of Paphlagonia and the Theme of Chaldia were split from the Armeniac Theme around 819 by Emperor Leo V and given their own naval squadrons, possibly to defend against Rus' attacks.

Important sea routes were managed by officials called archontes, who sometimes led parts of the Imperial Fleet. These included areas like Chios, Malta, the Euboic Gulf, and possibly Vagenetia and "Bulgaria". These positions disappeared by the late 800s, either due to Arab attacks or changes in organization.

Manpower and size

The exact size of the Byzantine navy and its units is hard to know because of limited and unclear records. For the late 900s and early 1000s, we have more details from the Cretan expedition of 911. During Emperor Leo VI’s rule, the navy had about 34,200 oarsmen and maybe 8,000 marines. The central Imperial Fleet had around 19,600 oarsmen and 4,000 marines. These marines were professional soldiers, first hired by Basil I in the 870s. They were important because they were well-trained and ready when needed. The Aegean thematic fleet had 2,610 oarsmen and 400 marines, the Cibyrrhaeot fleet had 5,710 oarsmen and 1,000 marines, the Samian fleet had 3,980 oarsmen and 600 marines, and the Theme of Hellas had 2,300 oarsmen and some of its 2,000 soldiers acted as marines.

Contrary to popular belief, the Byzantines and Arabs did not use slaves as rowers. Crews were mostly free lower-class men who were professional soldiers, legally required to serve in exchange for pay or land. In the 900s, land grants were worth 2–3 pounds of gold for sailors and marines. Prisoners of war and foreigners were also used. Groups like the Mardaites and the mysterious Toulmatzoi (possibly Dalmatians) appeared in Cretan expeditions, along with many Rus', who were allowed to serve in the Byzantine army under 10th-century treaties.

Emperor Constantine Porphyrogenitos gave fleet lists for the Crete expeditions of 911 and 949. These have caused much debate about how to understand them. The numbers for the entire Imperial Fleet in 949 can be seen as 100, 150, or 250 ships, depending on how the Greek text is read. The meaning of the word ousia is also unclear: it might mean a standard group of 108 men or simply “unit” or “ship”. Most scholars accept 150 as the more likely number, though they differ on the fleet’s makeup. Warren Treadgold estimates around 240 warships for the total navy in this period, increasing to 307 for the Cretan expedition of 960–961. This probably shows the standing strength of the whole Byzantine navy in the 900s and 1000s. However, there was a noticeable decrease in ships and men in thematic fleets between 911 and 949. This drop, reducing thematic fleets from a third to a quarter of the total navy, was partly due to using lighter ousiakos ships instead of heavier dromons and partly due to financial and manpower issues. This trend continued, leading to the disappearance of provincial fleets by the late 1100s.

Rank structure

Though naval themes were organized like land themes, Byzantine sources are unclear about the exact rank structure. The usual term for admiral was strategos, the same as for land generals governing themes. Under the strategos were two or three tourmarchai (effectively ‘vice admirals’), who oversaw several droungarioi (corresponding to ‘rear admirals’). Until the mid-800s, the governors of the Aegean and Samos themes were also called droungarioi, since their commands came from the original Karabisianoi fleet, but they were later raised to the rank of strategos. As thematic admirals also governed their themes, they were helped by a protonotarios (chief secretary) who managed the civilian administration. Other staff officers included the chartoularios for fleet administration, the protomandator (chief messenger) as chief of staff, and several kometes (‘counts’), including a komes tes hetaireias who led the admiral’s bodyguard (hetaireia).

The Imperial Fleet was different because it was not tied to thematic administration but was one of the tagmata, the professional central reserve forces. So, the commander of the Imperial Fleet was called the droungarios tou basilikou ploïmou (later with the prefix megas, ‘grand’). Originally a low rank, this position rose quickly: by 899, he was placed just before or after the logothetes tou dromou, and ahead of many senior military and civil officials. He was also notable for not being grouped with other military commanders, whether of the themes or the tagmata, but in the special class of military officials, the stratarchai, where he was listed second after the hetaireiarches, the commander of the imperial bodyguard. His title was still used in the Komnenian era, though as commander of the imperial escort squadron, and survived until the Palaiologan era, appearing in the 14th-century Book of Offices by Pseudo-Kodinos. The role of a deputy called topoteretes for the Imperial Fleet is also mentioned, but his duties are unclear from the sources. He might have had a role similar to a port admiral. Though some senior officers were professional sailors who rose through the ranks, most fleet commanders were high court officials who relied on their more experienced professional subordinates for sailing knowledge.

In lower levels, there was more consistency: squadrons of three or five ships were led by a komes or droungarokomes, and each ship’s captain was called kentarchos (‘centurion’), though literary sources also used older terms like nauarchos or even trierarchos. Each ship’s crew, depending on its size, had one to three ousiai. Under the captain were the bandophoros (‘banner bearer’) as executive officer, two protokaraboi (sing. protokarabos, ‘first ship-man’), sometimes also called kybernetes, and a bow officer, the proreus. The protokaraboi were helmsmen, in charge of the steering oars in the stern and the rowers on either side of the ship. The senior of the two was the “first protokarabos (protos protokarabos). In practice, there were likely several of each type of officer on each ship, working in shifts. Most of these officers came up from the ranks, and there are mentions in De Administrando Imperio of first oarsmen (protelatai) who became protokaraboi in imperial barges and later took on higher offices; Emperor Romanos Lekapenos was the most successful example. There were also specialists on board, such as the two bow oarsmen and the siphonatores, who worked the siphons used for Greek fire. A boukinator (trumpeter) is also recorded in the sources, who gave orders to the rowers (koplatai or elatai). Since marine infantry were organized as regular army units, their ranks followed those of the army.

Late period (1080s–1453)

Reforms of the Komnenoi

After the navy weakened in the 1000s, Alexios I rebuilt it in a new way. With the thematic fleets almost gone, their remains were combined into one imperial fleet, led by the new office of the megas doux. The first known megas doux was Alexios’ brother-in-law John Doukas around 1092. The megas droungarios tou ploïmou, once the top naval commander, was now under him, acting as his main helper. The megas doux was also the overall governor of southern Greece, the old themes of Hellas and the Peloponnese, which were split into districts (oria) that supplied the fleet. Under John II, the Aegean islands also had to help maintain, crew, and supply warships, and writers at the time proud of the fact that the big fleets of Manuel’s time were manned by “native Romans”, though they still used mercenaries and allied squadrons. However, because the fleet was now only based in Constantinople and provincial fleets were not rebuilt, outer areas like Greece were left open to attack.

Nicaean navy

With the Byzantine fleet weakening in the late 1200s, the Empire increasingly depended on the fleets of Venice and Genoa. After the sack of 1204, records suggest a fairly strong fleet under the first Nicaean emperor, Theodore I Laskaris, though exact details are scarce. Under John III and Theodore II (r. 1254–1258), the navy had two main areas of operation: the Aegean, for actions against the Greek islands (mainly Rhodes) and moving and supplying armies in the Balkans, and the Sea of Marmara, where the Nicaeans tried to stop Latin shipping and threaten Constantinople. Smyrna was the main shipyard and base for the Aegean, with a smaller one at Stadeia, while the main base for the Marmara Sea was Holkos, near Lampsakos across the Gallipoli peninsula.

Palaiologan navy

Despite their efforts, the Nicaean emperors could not challenge Venetian control of the seas and had to ask the Genoese for help. After regaining Constantinople in 1261, Michael VIII worked hard to reduce this dependence by building a “national” navy, creating new groups for this purpose: the Gasmouloi, men of mixed Greek-Latin descent living around the capital; and men from Laconia, called Lakones or Tzakones, were used as marines, forming most of the Byzantine naval forces in the 1260s and 1270s. Michael also separated the rowers, called Prosalentai or Proselontes, into their own group. All these groups got small land grants to farm in return for their service and lived together in small colonies. The Prosalentai were settled near the sea all over the northern Aegean, while the Gasmouloi and Tzakones were mostly around Constantinople and in Thrace. These groups lasted, though in smaller numbers, through the Empire’s last centuries; the Gasmouloi of Gallipoli made up most of the crews of the first Ottoman fleets after the Ottomans took the area. Through the Palaiologan period, the fleet’s main base was the harbor of Kontoskalion on the Marmara side of Constantinople, which Michael VIII deepened and fortified. Among provincial naval centers, Monemvasia in the Peloponnese was probably the most important.

At the same time, Michael and his successors kept the long-standing practice of using foreigners in the fleet. Along with the distrusted Italian city-states, whose alliances changed often, mercenaries were more and more used in the Empire’s last centuries, often rewarded with fiefs for their services. Most of these mercenaries, like Giovanni de lo Cavo (lord of Anafi and Rhodes), Andrea Morisco (successor of de lo Cavo in Rhodes) and Benedetto Zaccaria (lord of Chios and Phocaea), were Genoese, the Byzantines’ main ally at the time. Under Michael VIII, for the first time a foreigner, the Italian privateer Licario, became megas doux and was given Euboea as a fief. In 1303, another new rank, amerales (ἀμηράλης or ἀμηραλῆς), was created. The term was already used in Byzantine language from contact with the Kingdom of Naples and other Western nations, but it was rarely used; it was added to the imperial hierarchy with the arrival of the mercenaries of the Catalan Company. Only two holders are known, Ferran d'Aunés and Andrea Morisco, both from 1303 to 1305, though the rank was mentioned in lists of offices long after that. So, according to the mid-14th century Book of Offices, the subordinates of the megas doux were the megas droungarios tou stolou, the ameralios, the protokomes, the junior droungarioi, and the junior kometes. Pseudo-Kodinos also notes that, while other warships flew “the usual imperial flag” of the cross and the firesteels, the megas doux flew an image of the emperor on horseback as his special symbol.

Ships

Dromons and their derivatives

Further information: Dromon

The main warship of the Byzantine navy until the 12th century was the dromon and similar ships. The word "dromon" comes from a Greek word meaning "runner," showing that these ships were known for their speed. These ships evolved from earlier Roman ships and were used in many sea battles, especially against the Arabs.

Evolution and features

Learning about these old warships is difficult because few actual ships have been found. Most information comes from old writings and pictures. In recent years, digs in Istanbul uncovered remains of over 36 Byzantine ships from the 6th to 10th centuries, including some light warships.

Early dromons were different from earlier ships because they had a full deck, gave up ramming the front of the ship for a different kind of spike, and began using special sails called lateen sails. These changes made the ships stronger and better for sailing.

The dromons described by the writer Procopius had one level of oars, with 25 oars on each side. Later ships had two levels of oars. These ships were about 32 meters long and had one or two masts. They were steered by rudders at the back and had a special tent for the captain. The front of the ship had a raised area and a tube for shooting a very hot, sticky liquid called Greek fire.

The four ships found in Istanbul from the 10th–11th centuries were all built in a similar way, suggesting a centralized process for making them. They were about 30 meters long and made from special kinds of wood.

Ship types

By the 10th century, there were three main types of two-oar-bank warships: the chelandion ousiakon, the chelandion pamphylon, and the dromon. These ships had different numbers of crew members. There was also a smaller ship called the moneres or galea, used for scouting and in battles. Some larger ships may have had three levels of oars, but this is not certain.

For carrying goods, the Byzantines usually used regular merchant ships. They also used special ships for carrying horses, which were either sailing ships or oared ships. These horse-carrying ships were different from the main war ships.

Western designs of the last centuries

Eventually, the Byzantines began using ships based on Western designs. By the 13th century, the term dromon was replaced by katergon, which originally referred to the crews. Byzantine ships during this time were similar to Western ships, and the horse-carrying ships were replaced by Western designs called taride.

From the late 13th century, most Mediterranean ships had three men on each oar bank, a style called the alla sensile system. The Venetians also developed larger ships for carrying trade goods.

During the 1437 journey of the Byzantine delegation to the Council of Florence, most ships were Venetian or Papal, but Emperor John VIII travelled on an "imperial ship" that was noted for being faster than the Venetian merchant ships. A writer named Michael of Rhodes wrote a book on shipbuilding that described the main ships used by Venice and other sea states in the first half of the 15th century.

Tactics and weapons

The Byzantines carefully recorded and shared their knowledge of fighting on land and sea through special books called military manuals. These books, even with old-fashioned words, help us understand how Byzantine sailors fought. Important books include parts from Leo the Wise and Nikephoros Ouranos, who used older works to share their ideas.

Byzantine ships, called galleys, could not sail well in rough seas or carry much water. They depended on calm weather and close-to-shore routes. Battles were usually small and close to land, aiming to capture islands or coastal areas rather than control large areas of the ocean. Sailors used clever tricks to surprise enemies and avoided fighting unless they felt sure of winning.

During battles, ships tried to stay in order so they could help each other. They used tricks like pretending to run away to confuse the enemy. When ships got close, they threw things like fire and arrows to weaken the other team before fighting hand-to-hand. Soldiers on the ships wore strong armor and used weapons like swords and spears.

The Byzantines used special fire called “liquid fire” that could burn on water. It was shot from tubes on their ships and was very scary to enemies. Though it was useful sometimes, it was not always easy to use because it needed calm weather. Other tools included small catapults that threw stones, arrows, and even pots of fire. Soldiers also used crossbows, which became more important later.

Role of the navy in Byzantine history

The Byzantine navy played a very important role in the history of the Byzantine Empire. The Empire had a long coastline to defend and many of its big cities and rich lands were near the sea. Because ships were the fastest and cheapest way to travel, having a strong navy was very important, especially when faced with threats from the Arabs between the 7th and 10th centuries.

The navy helped protect the city of Constantinople during two big attacks by the Arabs, which helped save the Empire. Naval battles were a regular part of the fights against the Arabs, with both sides winning and losing over time. Even though the Byzantines had some amazing victories, like a nighttime win in 880, things were not always perfect. Sometimes sailors in the navy were unhappy with their conditions, and the navy was often seen as less important than the army. As time went on, the Byzantine navy grew weaker, especially when Italian cities like Venice and Genoa became more powerful. This weakness made it hard for the Empire to defend itself, and it had a big effect on the Empire's future. Strong leaders tried to bring back the navy's power, but the Empire still struggled without control of the sea.