World War I

World War I, or the First World War, lasted from 28 July 1914 to 11 November 1918 and was also known as The Great War. It was a global conflict between two coalitions: the Allies (or Entente) and the Central Powers. Major fighting happened in Europe, the Middle East, Africa, and the Asia-Pacific regions. The war saw new and powerful weapons such as tanks, aircraft, artillery, machine guns, and chemical weapons.

The war began after the assassination of Franz Ferdinand, heir to the Austro-Hungarian throne, by Gavrilo Princip, a Bosnian Serb, on 28 June 1914. This event led Austria-Hungary to declare war on Serbia, which then pulled in other countries due to existing alliances. Russia mobilized to support Serbia, causing Germany to declare war on Russia and France. The United Kingdom entered the war when Germany invaded Belgium. Over time, more countries joined, including Italy, Bulgaria, Romania, Greece, and, in 1917, the United States after Germany resumed unrestricted submarine warfare.

The war was one of the deadliest in history, with an estimated 15 to 22 million military and civilian casualties. It also led to the Spanish flu pandemic due to the movement of large numbers of people. Fighting on the Western Front became stuck in trenches, with major battles like Verdun, the Somme, and Passchendaele failing to change the situation. In 1918, Germany launched an offensive in the spring but was eventually defeated by the Allied Hundred Days Offensive. The war ended with the Armistice of 11 November 1918.

The Paris Peace Conference of 1919–1920 created new treaties, including the Treaty of Versailles, which required Germany to give up land, disarm, and pay reparations. The war led to the end of several empires and the creation of new countries such as Poland, Finland, the Baltic states, Czechoslovakia, and Yugoslavia. The League of Nations was formed to help keep peace, but its struggles later contributed to the start of World War II in 1939.

Names

Before World War II, the conflict from 1914 to 1918 was often called the Great War or simply the World War. At the time, people believed it might be the last big war ever. The term First World War was first used in September 1914 by a German scientist who thought this war would be the first true world war.

Background

Main article: Causes of World War I

For much of the 1800s, European countries tried to keep peace through a balance of power. However, changes like the rise of Germany and the decline of the Ottoman Empire created new tensions. Countries formed alliances to protect their interests. Germany and Austria-Hungary formed the Triple Alliance, while France, Russia, and Britain created the Triple Entente. These alliances set the stage for future conflict.

Germany's growing economy led to an arms race, especially with Britain over naval power. This competition, along with rising tensions in the Balkans, made war more likely. The Balkans were unstable, with many countries wanting control of the region. Conflicts like the Balkan Wars increased anger and mistrust among nations, making the outbreak of a larger war a concern.

Prelude

For a chronological guide, see Timeline of World War I.

Sarajevo assassination

Main article: Assassination of Archduke Franz Ferdinand

On 28 June 1914, Archduke Franz Ferdinand of Austria, who was next in line to become emperor, was visiting Sarajevo, the capital of Bosnia and Herzegovina, which had recently been taken over by Austria. A group of young men from a movement called Young Bosnia tried to stop him because they wanted Bosnia to be free from Austrian control. One of them, Gavrilo Princip, shot and killed the Archduke and his wife, Sophie.

Expansion of violence in Bosnia and Herzegovina

Austro-Hungarian authorities encouraged subsequent anti-Serb riots in Sarajevo. Violent actions against ethnic Serbs were also organised outside Sarajevo, in other cities in Austro-Hungarian-controlled Bosnia and Herzegovina, Croatia and Slovenia.

July Crisis

Main article: July Crisis

See also: German entry into World War I, Austro-Hungarian entry into World War I, and Russian entry into World War I

The killing of the Archduke started what is called the July Crisis. Austria wanted to use this chance to stop Serbia from interfering in Bosnia, and they saw war as a way to do this. On 23 July, Austria gave Serbia a list of demands that were impossible to accept, hoping this would give them an excuse to start fighting. When Serbia did not accept all the demands, Austria declared war on Serbia on 28 July. Russia, to support Serbia, began preparing its army. Germany, fearing a war on two fronts, also started preparing its army. Soon, many countries were involved, and World War I had begun.

Progress of the war

Further information: Diplomatic history of World War I

World War I, also known as The Great War, was a global conflict between two coalitions: the Allies (or Entente) and the Central Powers. The war lasted from 28 July 1914 to 11 November 1918 and involved major areas of conflict including Europe, the Middle East, parts of Africa, and the Asia-Pacific.

The war saw important developments in weaponry, including tanks, aircraft, artillery, machine guns, and chemical weapons. The conflict began with the assassination of Archduke Franz Ferdinand of Austria and quickly escalated as alliances drew more nations into the fight. Key battles and campaigns shaped the course of the war, including the Serbian campaign, the German offensive through Belgium and France, and trench warfare on the Western Front. The war also saw action in the Balkans, the Ottoman Empire, and the Italian Front, with significant battles influencing the strategic balance. The entry of the United States in 1917 shifted the tide, and the final years of the war saw major offensives and the eventual collapse of the Central Powers, leading to armistices and the end of the conflict.

Aftermath

Main article: Aftermath of World War I

After World War I ended, big changes happened across Europe. The German, Austro-Hungarian, Ottoman, and Russian empires all disappeared, and many new countries were created. Some families that had ruled for a long time lost their power. Belgium, Serbia, and France were badly damaged, and many soldiers lost their lives.

The war officially ended with several treaties. The most famous one was the Treaty of Versailles, signed in 1919, which placed many rules on Germany. This treaty created the League of Nations to help keep peace in the future. Different countries signed their own peace treaties to officially end the war, with some signing as late as 1924.

Casualties

Further information: Spanish flu

World War I was one of the deadliest conflicts in history, with estimates suggesting around 15 to 22 million people died, including both soldiers and civilians. Many were also wounded, and the war caused huge changes in how battles were fought, with new weapons like tanks and airplanes.

The war also brought diseases, like a serious flu called the Spanish flu, which spread worldwide and caused many more deaths. Soldiers from all sides faced hard conditions, and many were taken as prisoners, though most survived in prisoner-of-war camps.

Soldiers' experiences

During World War I, millions of soldiers from both sides served in the conflict. Many soldiers who survived the war found it hard to share their experiences with others and often formed groups just for veterans to talk to each other.

Conscription, or forced military service, was used in many countries. This was especially controversial in places like Ireland, Australia, and Canada. In the United States, conscription began in 1917 and was needed because not enough people were volunteering to fight.

Main articles: List of military attachés in World War I and List of military attachés and war correspondents in World War I

Economic effects

Main articles: Economic history of World War I and Post–World War I recession

Further information: Home front during World War I and Financial crisis of 1914

World War I changed economies in many countries. With many men going to war, women entered the workforce in large numbers for the first time, which helped later efforts for voting rights for women. Governments took on larger roles in their economies, with their share of the total wealth rising above 50% in places like Germany and France.

Countries borrowed heavily to pay for the war. Britain sold investments in the United States and borrowed from Wall Street. After the war, the U.S. asked for its loans to be repaid, which created financial challenges for many nations. The Great Depression later made it even harder to pay back these debts.

Support and opposition for the war

Further information: Propaganda in World War I, British propaganda during World War I, and Propaganda and censorship in Italy during the First World War

Many groups and individuals supported World War I for various reasons. In the Balkans, Yugoslav nationalists wanted freedom from Austria-Hungary and hoped to create an independent Yugoslavia. In the Middle East, Arab nationalism grew, leading to the Arab Revolt against Ottoman rule. Some socialist parties initially supported the war, though they later divided over the issue.

Opposition to the war also existed. Some people were jailed for speaking out against it, including Eugene Debs in the US and Bertrand Russell in Britain. In Ireland, some Irish nationalists opposed joining the war, which contributed to tensions and events like the Easter Rising in 1916. Others, known as conscientious objectors, refused to fight for personal or religious reasons and faced severe penalties.

Technology

World War I saw many new technologies used in battle. Armies started using telephones, wireless communication, armoured cars, tanks like the Little Willie, and aircraft. Poison gas was also used, becoming one of the most feared weapons, although it was not decisive in winning the war.

Artillery changed greatly during the war. At first, cannons were placed close to the front lines, but later, indirect fire techniques were used, with help from aircraft and field telephones. Fixed-wing aircraft were first used for spotting the enemy and attacking from the ground. To fight these planes, anti-aircraft guns and fighter aircraft were developed. Strategic bombers were created by both the Germans and British, and for the first time, aircraft carriers were used in combat.

Diplomacy

Main article: Diplomatic history of World War I

During World War I, countries used diplomacy and propaganda to gain support for their causes or weaken their enemies. They focused on several key areas: running propaganda campaigns, changing their war goals as the conflict continued, trying to bring neutral countries like Italy, the Ottoman Empire, Bulgaria, and Romania to their side by promising land, and supporting groups within enemy countries who wanted independence. There were also many peace offers from neutral countries or from one side to the other, but none of these led to real progress toward ending the war.

Legacy and memory

Main articles: List of last surviving World War I veterans, Commonwealth War Graves Commission, and American Battle Monuments Commission

Memorials were built in thousands of villages and towns to honor those who served and died in the war. Organizations like the Commonwealth War Graves Commission and the American Battle Monuments Commission helped move soldiers buried near battlefields to formal graveyards and built monuments to those who were missing. The poem In Flanders Fields by John McCrae is still remembered today, especially on special days of remembrance.

Historians continue to study World War I to understand its causes and effects. The war was different from later conflicts because it didn’t have clear heroes or villains, making it challenging to teach. Today, scholars explore many new ideas about the war, including its impact on politics, society, and everyday life.