Theban–Spartan War

The Theban–Spartan War of 378–362 BC was a series of battles fought between two powerful cities in ancient Greece: Sparta and Thebes. For many years, Sparta had been the strongest military power in Greece, but things changed when Thebes, led by a smart general named Epaminondas, stood up against Spartan rule.

In 371 BC, Epaminondas led his army to a big win at the Battle of Leuctra. This battle was very important because it showed that Sparta could be beaten, and it ended Sparta’s control over Greece. After this, Thebes became the new leader in Greece.

The war went on for several more years, with fighting in places like the Peloponnese. In 362 BC, there was another big battle at Mantinea, where Thebes won again, but Epaminondas was killed. Not long after, the war ended with a peace treaty. Sparta was left weaker and more alone, changing the balance of power in Greece forever.

Background

Sparta had won the Peloponnesian War against Athens and controlled much of Greece. But their harsh actions upset many allies, including Thebes and Corinth. This led to the Corinthian War, which ended with Sparta still in charge, though weakly.

After this war, Sparta tried to rebuild its power and punish allies who had opposed them. In 385 BC, Sparta attacked Mantinea, breaking it into smaller parts. Later, they moved against Olynthus for breaking agreements. During this time, Spartan forces, led by Phoebidas, took control of Thebes' main fortress after being invited by a local leader who felt unsafe.

In 379 BC, Theban leaders like Pelopidas fled to Athens. They then led a group that surprised Thebes, overthrowing the leaders who supported Sparta and freeing the city from Spartan control.

379/378 BC – Theban coup

After a war called the Corinthian War, Thebes found itself weaker than before. In 382 BC, Spartan soldiers took control of Thebes' main fortress. This was done by trickery, and some of Thebes' leaders were forced to leave the city.

A group of Theban leaders who had been forced away returned secretly. Led by a man named Pelopidas, they entered Thebes and removed the leaders who supported Sparta. With help from another leader, Epaminondas, they prepared young men to defend their city. The Spartans inside the fortress were surrounded, and after a short fight, they agreed to leave Thebes safely. This event marked the beginning of Thebes standing up against Spartan control.

Boeotian War

The Boeotian War began in 378 BC when Thebes rebelled against Sparta. This war marked Thebes as a major power in Greece, challenging Sparta's control. By the war's end, Thebes' key leaders, Pelopidas and Epaminondas, had passed away, and Thebes' influence was already fading, making way for the rise of Macedon.

Outbreak (378 BC)

Sparta quickly sent forces led by King Cleombrotus to confront Thebes in the middle of winter. Cleombrotus had to enter Boeotia through Mount Cithaeron because the border fort of Eleutherae was guarded by Athenian soldiers. After moving through allied cities like Plataea and Thespiae, Cleombrotus set up camp at Cynoscephalae near Thebes. Athens, worried by Cleombrotus's nearby presence, punished their own leaders who supported Thebes' rebellion. Thebes tried to negotiate with Sparta to rejoin the Peloponnesian League, but Sparta demanded harsh terms that Thebes refused.

Cleombrotus's efforts to negotiate led nowhere. After 16 days, with no challenge from Thebes or Athens, he withdrew without fighting, retreating through Creusis and Aigosthena. Athens later became fully allied with Thebes after a Spartan attack on their port of Piraeus by a commander named Sphodrias, which Sparta did not properly explain or punish.

Invasions of Agesilaus II

Sparta gathered its allies and, under King Agesilaus, invaded Boeotia in the spring of 378. The Thebans, led by Gorgidas, built defenses around their city to resist. The Sacred Band, a special Theban unit, saw its first action here during a standoff with the Athenian commander Chabrias and Agesilaus. Athens had previously helped Theban forces retake Thebes from Sparta. In the summer, Agesilaus led a large Spartan force against Thebes from Thespiae. The Thebans and Athenians set up defenses to stop the Spartans.

Agesilaus tried to provoke a battle but was outsmarted by Chabrias, who had his soldiers rest calmly when the Spartans approached. This surprised Agesilaus, who then decided not to fight and instead destroyed Theban land before withdrawing. After Agesilaus left, his commander Phoebidas continued to attack Theban areas, but was eventually killed by Theban forces under Gorgidas.

Spartan setbacks

In 376 BC, King Cleombrotus tried to cross the Cithaeron Mountains to attack Thebes but was blocked. This allowed Thebes to conquer Spartan strongholds in Boeotia and lose only a small part of their land. Sparta then tried to block Athenian support by sea, but their fleet was defeated by the Athenian commander Chabrias. Later, Athens conducted successful raids in other areas.

Battle of Tegyra

The Sacred Band's first major victory was at the Battle of Tegyra in 375 BC, near Orchomenus. Pelopidas led the Thebans to surprise a smaller Spartan force, defeating them and boosting Theban confidence. This battle showed that Spartan forces could be beaten and raised Theban morale.

378–371 BC – Aftermath

After Thebes' rebellion, Sparta sent armies to attack but failed. The Thebans built defenses and gradually became stronger. By 371 BC, Thebes had united Boeotia into a federation, making the names Theban and Boeotian used interchangeably. Leaders like Pelopidas pushed for aggressive action against Sparta.

Peace conferences

Fighting continued until 375 BC when a peace agreement was made but quickly broke down. In 371 BC, another peace conference failed when Theban leader Epaminondas insisted on signing for all Boeotians, not just Thebes. This led to renewed war.

Battle of Leuctra (371 BC)

The failed peace talks led to the Battle of Leuctra. Spartan King Cleombrotus marched into Boeotia and set up camp at Leuctra. Theban leader Epaminondas used clever tactics, placing his best troops in an unusual formation. The Theban cavalry defeated the Spartan cavalry, and the Theban infantry, led by Epaminondas and the Sacred Band, overwhelmed the Spartans. The Spartans lost heavily, including many elite warriors, ending their dominance in Greece and beginning Theban leadership.

Theban hegemony

Main article: Theban hegemony

After winning a big battle, the Thebans wanted to punish Sparta but their friends talked them out of it. Instead, their leader, Epaminondas, worked on making Thebes stronger by bringing together nearby cities.

The next year, the Thebans went to a place called the Peloponnese to weaken Sparta further. They wanted to replace Sparta’s power with their own. Over time, Thebes built strong friendships in central Greece but didn’t try to control faraway places.

First Invasion of the Peloponnese (370 BC)

When the Thebans told Athens about their victory, Athens used the chance to make peace with the cities Sparta used to control. This made some cities want to join together, which upset Sparta. The Thebans, led by Epaminondas, arrived and helped these cities form a new group. They also built a new city called Megalopolis as a base against Sparta.

The Thebans crossed into Sparta’s land and caused damage but didn’t try to capture the city. They then went to a place called Messenia, freed the people there, and built a new city named Messene. Losing Messenia hurt Sparta a lot because it was a big part of their land and workers.

Trial

Epaminondas had to stay longer than usual to achieve his goals, so when he returned, some people in Thebes put him on trial. But when he defended himself, everyone laughed, and the charges were dropped. He was chosen to lead again the next year.

Second invasion of the Peloponnese (369 BC)

The next year, the Thebans returned to help their friends against Sparta. They fought through a guarded area and joined their allies. They made some cities their friends but couldn’t capture others. After facing new soldiers sent to help Sparta, they went home.

Thessaly (368 BC)

When Epaminondas went home, some people in Thebes accused him again. This time, they didn’t let him lead for a year. Later, he helped free two Theban friends who were captured and brought them back safely.

Third invasion of the Peloponnese (367 BC)

Epaminondas went to a place called Achaea to make them friends with Thebes. Some people didn’t like this, so they changed their minds later and started supporting Sparta again.

Achaemenid attempt at mediation (368–366 BC)

Some people tried to make peace with help from a faraway king, but Thebes didn’t agree to give back Messenia, so the peace talks failed. After that, the king helped Sparta with money and soldiers.

Resistance to Thebes

Over time, some of Thebes’ friends stopped liking them and made friends with Sparta instead. But Thebes kept making new friends and even tried to challenge Athens at sea. One of Epaminondas’ close friends was lost in a battle, making things harder for him.

Fourth invasion of the Peloponnese (362 BC)

Main article: Battle of Mantinea (362 BC)

Because more and more cities were against Thebes, Epaminondas went on one last trip to a place called Mantinea. Many cities from all over Greece got ready to fight. Epaminondas planned a smart attack and caught the other side by surprise. Even though he won the battle, he was hurt badly and died soon after. After his death, neither side won more land or power, and Greece stayed unsettled.

Athens and the Theban Wars

Sparta invaded Thebes in 382 BC, which led Thebes to join a league. However, Athens began to distrust Thebes, especially after Thebes destroyed the town of Plataea in 372 BC. Around this time, Athens considered making peace with Sparta. But in 378 BC, when Sparta tried to take control of Piraeus, Athens moved closer to Thebes.

Athens and Thebes became allies and formed the Second Athenian League, which included many cities in Boeotia and some islands. In 376 BC, the Athenian commander Chabrias won a naval battle against Sparta near the island of Naxos. Later, Athens tried to leave the war but had to help Sparta when Sparta attacked the island of Corcyra. The Athenian general Timotheus helped Corcyra and won a battle against Sparta at sea.

When a peace meeting happened in 371 BC, Athens supported Sparta's decision not to let Thebes speak for all of Boeotia. Athens was not happy when Thebes defeated Sparta at the Battle of Leuctra, as they worried Thebes was becoming too powerful. After this victory, Thebes and the Persians became allies again. When Sparta invaded a region called Arcadia in 370 BC, Arcadia first asked Athens for help, but turned to Thebes when Athens did not help. This led to Thebes entering a part of Greece called the Peloponnese for the first time.

Second Athenian League won a naval victory