World War I

World War I, also called the First World War or the Great War, was a global conflict fought from 28 July 1914 to 11 November 1918. It was fought between two coalitions: the Allies (or Entente) and the Central Powers. It was one of the deadliest conflicts in history, and many people died. The war also helped spread the Spanish flu pandemic. It brought new weapons, including machine guns, artillery, aircraft, chemical weapons, and tanks.

The causes of World War I included the rise of the German Empire, which upset the long-standing balance of power in Europe. Rivalries between countries grew stronger. New alliances formed, and an arms race began among the great powers. On 28 June 1914, tensions in the Balkans reached a breaking point. Gavrilo Princip, a Bosnian Serb, assassinated Franz Ferdinand, who was heir to the Austro-Hungarian throne. Austria-Hungary blamed Serbia and declared war. The Russian Empire prepared to defend Serbia. Germany then declared war on Russia and France. The United Kingdom joined the war after Germany invaded Belgium. On the Western Front, the armies settled into long lines of trenches that stretched from the English Channel to Switzerland. The Eastern Front was more active, but neither side won a clear advantage. The Ottoman Empire joined the Central Powers. Japan and Italy joined the Allies. A major Allied campaign at Gallipoli failed.

Huge battles at Verdun, the Somme, and Passchendaele did not break the stalemate on the Western Front. In April 1917, the United States joined the Allies after Germany resumed unrestricted submarine warfare against Atlantic shipping. Later that year, the Bolsheviks took power in Russia during the October Revolution. Soviet Russia signed an armistice with the Central Powers, and then made a separate peace in March 1918. That spring, Germany launched a spring offensive in the west. It had early successes, but it left the German Army worn out and discouraged. Beginning in August 1918, the Allied Hundred Days Offensive caused the German front line to collapse. By early November, the Allies had signed armistices with the Ottomans and with Austria-Hungary, which left Germany alone. Facing a revolution at home, Kaiser Wilhelm II abdicated on 9 November. The war ended with the Armistice of 11 November 1918.

The Paris Peace Conference of 1919–1920 set the terms for the defeated powers. Under the Treaty of Versailles, Germany lost large areas of land, was disarmed, and had to pay large war reparations to the Allies. The collapse of the Russian, German, Austro-Hungarian, and Ottoman empires led to new national borders and new independent countries. These included Poland, Finland, the Baltic states, Czechoslovakia, and Yugoslavia. The League of Nations was created to keep world peace, but it could not manage the instability of the interwar period. This helped lead to the start of World War II in 1939.

Other terms that also lead to this article include WWI (disambiguation), The First World War (disambiguation), World War One (disambiguation), and Great War (disambiguation).

Names

Before World War II, the events of 1914–1918 were often called the Great War or simply the World War. In August 1914, The Independent said of the conflict, "This is the Great War. It names itself." In the years after it ended, many people hoped it would be "the war to end all wars," because it had caused so much destruction and loss.

The earliest known use of the term First World War appeared in September 1914. German biologist and philosopher Ernst Haeckel wrote that the ongoing "European War" would become "the first world war in the full sense of the word."

Background

Main article: Causes of World War I

For much of the 19th century, the major European powers kept a fragile balance of power, known as the Concert of Europe. After 1848, this peace was tested by Britain's splendid isolation, the decline of the Ottoman Empire, New Imperialism, and the rise of Prussia under Otto von Bismarck. Prussia won the Franco-Prussian War in 1870–1871. This helped Bismarck consolidate a German Empire. France wanted to avenge this defeat and grow its France's colonial empire.

Bismarck made agreements to keep the powers from fighting each other. In 1873, he created the League of the Three Emperors, which included Austria-Hungary, Russia, and Germany. After the Russo-Turkish War of 1877–1878, this league ended. Austria worried about Russian influence in the Balkans. Germany and Austria-Hungary then formed the Dual Alliance in 1879. Italy joined in 1882, and it became the Triple Alliance. In 1887, Bismarck also arranged a secret Reinsurance Treaty between Germany and Russia.

In 1890, Wilhelm II forced Bismarck to retire. His new Chancellor, Leo von Caprivi, did not renew the Reinsurance Treaty. France then agreed to the Franco-Russian Alliance in 1894. In 1904, France also made the Entente Cordiale with Britain. In 1907, the Anglo-Russian Convention completed the Triple Entente. These were not formal alliances. However, by settling longstanding colonial disputes in Asia and Africa, Britain could support France or Russia in a future conflict. This was shown when Britain and Russia supported France against Germany during the Agadir Crisis of 1911.

Germany's economy and industry grew quickly after 1871. With support from Wilhelm II, Admiral Alfred von Tirpitz wanted to build an Imperial German Navy that could compete with the Royal Navy. He based this plan on the ideas of US naval author Alfred Thayer Mahan, who argued that a blue-water navy was vital for global power. Bismarck had opposed competing with the Royal Navy. After he left office, the Anglo-German naval arms race began. In 1906, the launch of HMS Dreadnought made every existing battleship out of date. This gave Britain an advantage it never lost. In 1911, Chancellor Theobald von Bethmann Hollweg accepted defeat in the navy race. He moved spending from the navy to the army. Germans were worried about Russia getting stronger again after the Russo-Japanese War and the 1905 Russian Revolution. Germany added 170,000 troops to its army in 1913. France made military service longer, from two years to three. The years before 1914 also brought a series of crises in the Balkans, as powers tried to benefit from the Ottoman decline.

Russia was Pan-Slavic and Orthodox. It saw itself as the protector of Serbia, but it preferred that the Bosporus straits stay under a weak Ottoman government. Russia also had ambitions in northeastern Anatolia. Austria saw Serbian growth as a threat. In the Bosnian Crisis of 1908–1909, Austria took control of Bosnia and Herzegovina, which it had occupied since 1878. This happened at the same time as the Bulgarian Declaration of Independence. After the Italo-Turkish War, the Balkan League, made up of Serbia, Bulgaria, Montenegro, and Greece, took most Ottoman land in the Balkans during the First Balkan War. When Serbia captured ports on the Adriatic, Austria partly prepared its army, including units in Galicia. The Russian government chose not to respond. The Treaty of London in 1913 created an independent Albania. However, disagreements between the winners led to the Second Balkan War, in which Bulgaria lost most of Macedonia and Southern Dobruja. These tensions of resentment, nationalism, and insecurity helped make the Balkans known as the "powder keg of Europe."

Prelude

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

Main article: Assassination of Archduke Franz Ferdinand

On 28 June 1914, Archduke Franz Ferdinand of Austria, heir to Emperor Franz Joseph I of Austria, visited Sarajevo, the capital of the recently annexed Bosnia and Herzegovina. Several young men from the Young Bosnia movement waited along the route to attack him. They included Cvjetko Popović, Gavrilo Princip, Nedeljko Čabrinović, Trifko Grabež, Vaso Čubrilović and Muhamed Mehmedbašić. They had been given weapons by people in the Serbian Black Hand group, who hoped his death would free Bosnia from Austrian rule. Čabrinović threw a grenade at the Archduke's car, but it hurt only some of his helpers, and the other attempts failed. Later, Ferdinand's car took a wrong turn. Princip fired his gun, and Ferdinand and his wife Sophie were killed. Historian Zbyněk Zeman wrote that in Vienna the event almost made no impression. Historian Christopher Clark described it as a terrorist event that changed the political situation in Vienna.

Austro-Hungarian authorities encouraged anti-Serb riots in Sarajevo. Serbs were also treated badly in other cities in Bosnia and Herzegovina, Croatia and Slovenia. Many important Serbs were put in prison, and some were sentenced to death. A special police force, the Schutzkorps, was set up and mostly made up of Bosniaks. It carried out the harsh treatment of Serbs.

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 assassination started the July Crisis, a month of diplomatic talks among Austria-Hungary, Germany, Russia, France and Britain. Austrian officials believed Serbian intelligence had helped plan the attack. They saw war as the best way to stop Serbian interference in Bosnia, although the Foreign Ministry had no solid proof. On 23 July, Austria gave Serbia an ultimatum with ten demands that were meant to be impossible to accept, so that Austria would have a reason to start a war. Serbia accepted most of the demands but not all, and Austria broke off diplomatic relations. On 28 July, Austria declared war on Serbia and began attacking Belgrade. Russia ordered its army to prepare for war to support Serbia on 30 July. German Chancellor Bethmann Hollweg wanted support from the SPD political opposition, so he presented Russia as the aggressor and waited until 31 July to prepare for war. The German General Staff had long expected a war on two fronts. The Schlieffen Plan aimed to defeat France first and then turn to Russia. When the German ultimatum to Russia expired on 1 August, the two countries were at war. Britain's government was divided, but its promise to protect Belgium under the Treaty of London, along with the support of Prime Minister Asquith and public opinion, led Britain to act. French Commander-in-Chief Joseph Joffre was told not to cross into Belgium before a German invasion. On 2 August, Germany occupied Luxembourg. On 3 August, Germany declared war on France. Germany invaded Belgium early on 4 August, and Albert I of Belgium asked for help. When Britain's ultimatum, which demanded that Germany leave Belgium, expired at midnight without a response, Britain and Germany were at war.

Progress of the war

Further information: Diplomatic history of World War I

Fighting took place in many areas. On the Western Front, Germany tried to move through Belgium and France. In 1914, the advance was stopped, and both sides dug trenches to protect themselves. Battles such as Verdun and the Somme were very costly for both sides. At sea, Britain blocked Germany from trade, and Germany used submarines to attack Allied ships. The United States joined the Allies in April 1917. In the Balkans, Serbia held off Austria-Hungary in 1914. In 1915, Bulgaria joined the attack, and Serbia was defeated. Italy joined the Allies in 1915 and fought Austria-Hungary along the Italian Front. Russia's armies lost many battles, and unrest at home led to a revolution in 1917. In 1918, Russia made peace with Germany. The Allies then began to push the Central Powers back.

By the autumn of 1918, the Central Powers were falling apart. Bulgaria agreed to stop fighting on 29 September, and the Ottoman Empire surrendered on 30 October. Austria-Hungary also asked for an armistice. Italy's army advanced to Trento, Udine, and Trieste. In Germany, sailors revolted, and a republic was declared on 9 November 1918. Germany then surrendered. The armistice of 11 November 1918 ended the fighting.

Main article: Serbian campaign

Main articles: German invasion of Belgium (1914), Battle of the Frontiers, and Great Retreat

Main article: Asian and Pacific theatre of World War I

Main article: African theatre of World War I

Main article: Indian Army during World War I Further information: Hindu–German Conspiracy, Niedermayer–Hentig Expedition, and Third Anglo-Afghan War

Main article: Western Front (World War I)

Main article: Naval warfare of World War I

Main articles: Balkan Front (World War I), Bulgaria during World War I, Serbian campaign, and Macedonian front See also: Noemvriana

Main article: Ottoman Empire in World War I See also: Middle Eastern theatre of World War I

Main articles: Italian front (World War I), White War, and Military history of Italy during World War I

Main article: Eastern Front (World War I)

Main article: Romania in World War I For a chronological guide, see Timeline of World War I (1917–1918). Main articles: February Revolution, October Revolution, and Treaty of Brest-Litovsk

Main article: American entry into World War I Further information: Nivelle offensive and 1917 French Army mutinies

Main article: Sinai and Palestine campaign

Main article: German Caucasus expedition See also: Meuse-Argonne offensive

Main articles: Vardar offensive and Battle of Dobro Pole

Main articles: Armistice of Salonica, Armistice of Villa Giusti, and Armistice of Mudros Further information: Armistice of Belgrade

Main article: Armistice of 11 November 1918

Aftermath

Main article: Aftermath of World War I

Further information: Sykes–Picot Agreement

After the war, the German, Austro-Hungarian, Ottoman, and Russian empires were gone. Many nations won back their independence, and new countries were formed. Four royal families lost their power because of the war: the Romanovs, the Hohenzollerns, the Habsburgs, and the Ottomans. Belgium, Serbia, and France were badly damaged. Germany and Russia were also badly affected. The state of war continued for seven more months, until the Treaty of Versailles was signed with Germany on 28 June 1919. The US Senate did not approve the treaty. The US did not officially end its part in the war until the Knox–Porter Resolution was signed on 2 July 1921 by President Warren G. Harding. Some war memorials mark the end of the war as 1919, when many troops came home. Most remembrances focus on the armistice of 11 November 1918.

The Paris Peace Conference set a series of peace treaties for the Central Powers. The Treaty of Versailles dealt with Germany. It was based partly on Wilson's 14th point, and it created the League of Nations on 28 June 1919. Germany had to accept blame for the losses caused by the war. This statement, Article 231, became known as the "War Guilt Clause," and many Germans felt ashamed and angry. Austria-Hungary was split into several new countries. Russia lost much of its western land as Estonia, Finland, Latvia, Lithuania, and Poland became independent. After 123 years, Poland became an independent country again. The Kingdom of Serbia became the center of a new state, the Kingdom of Serbs, Croats and Slovenes, later renamed Yugoslavia. In Australia and New Zealand, the Battle of Gallipoli became their "Baptism of Fire," and Anzac Day now honors this moment. Greece later fought Turkish nationalists led by Mustafa Kemal. This led to a population exchange between the two countries under the Treaty of Lausanne.

Further information: Spanish flu

Many people died in World War I, and many more were wounded. It is one of the deadliest conflicts in human history. Many of the dead were military personnel, and many were civilian casualties. Many soldiers were killed, and many more were permanently disabled or seriously injured. Diseases spread easily in the chaotic conditions of war. In 1914, epidemic typhus caused many deaths in Serbia. From early 1918, the Spanish flu spread across the world and killed millions of people. Many equines, mostly horses, donkeys, and mules, also died.

The German army was the first to use chemical weapons successfully, at the Second Battle of Ypres in 1915. These weapons caused many casualties and deaths. They also broke the 1899 Hague Declaration Concerning Asphyxiating Gases and the 1907 Hague Convention on Land Warfare. During the war, the Ottoman Empire harmed and forced out many of its Armenian people. Historians call this genocide. The government of Turkey continues to deny the genocide today. Other groups were also harmed, including Anatolian and Pontic Greeks and Assyrian Christians. Many Assyrian Christians were killed. Many soldiers surrendered and were held in POW camps. Most of the prisoners were treated under the Hague Conventions.

Soldiers' experiences

Millions of people served in the Allied forces, and millions more served in the Central Powers. British soldiers first volunteered, but over time more were called up into the army. Many European countries used conscription, meaning the government required men to serve. In English-speaking countries, it was controversial. It was especially unpopular among some minority groups, such as Irish Catholics in Ireland and Australia and French Catholics in Canada. In the US, conscription began in 1917. Many people still opposed it, especially in rural areas and in the South. The government relied on conscription because too few volunteers joined in the first six weeks of the war. Veterans returning home often found that only other veterans understood what they had been through. So they formed "veterans' associations" or "Legions."

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

Military and civilian observers from many countries watched the war closely. Many were able to report on events from positions somewhat like the modern "embedded" reporters who travel with soldiers.

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

The war changed families and work. Many men were away fighting, so women took on many jobs. Industry also needed to replace workers who had gone to war. This move of women into factories and into jobs that were once mostly for men helped the struggle for voting rights for women.

In every nation, the government took a bigger share of the economy. Britain sold its American railroad investments and borrowed a lot of money from Wall Street. Meanwhile, US government lending to the Allies grew a great deal. After the war, the United States asked to be repaid, and Britain still owed $4.4 billion in 1934. Britain also turned to its colonies. Geologist Albert Kitson found new deposits of manganese, a metal used to make weapons, in the Gold Coast. Germany had to pay reparations, but payments were stopped in 1932 after the Great Depression caused trouble around the world. When Adolf Hitler came to power, the bonds and loans from the 1920s were cancelled. Writer David Andelman noted that "Refusing to pay doesn't make an agreement null and void." At the London Conference in 1953, Germany agreed to start payments again. It made its final payment on these bonds on 3 October 2010. Australian prime minister Billy Hughes wrote to British prime minister David Lloyd George to say he was sorry that better terms could not be won.

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 people supported the war. In the Balkans, Yugoslav nationalists such as leader Ante Trumbić wanted Yugoslavs to be free from Austria-Hungary and other foreign powers. They hoped for an independent Yugoslavia. The Yugoslav Committee, led by Trumbić, was formed in Paris in April 1915 and soon moved to London. In the Middle East, Arab nationalism grew in Ottoman lands, and Arab leaders called for a pan-Arab state. In 1916, the Arab Revolt began in Ottoman-controlled areas to win independence. In East Africa, Iyasu V of Ethiopia supported the Dervish state, which was at war with the British in the Somaliland campaign. Ethiopia came close to joining the Central Powers, but Iyasu was overthrown at the Battle of Segale after pressure from the Allies.

Several socialist parties first backed the war in August 1914. Later, European socialists split along national lines and followed their countries into the war. In Italy, Italian nationalism had strong support. Gabriele D'Annunzio promoted Italian irredentism, and the Italian Liberal Party, led by Paolo Boselli, wanted Italy to join the Allies. Benito Mussolini and Leonida Bissolati were strong supporters of the war among socialists. The Italian Socialist Party later opposed the war after some anti-war protesters were killed. This led to a general strike called Red Week. In October 1914, Mussolini started the pro-war paper Il Popolo d'Italia, with money from Ansaldo, a weapons company. His group later grew into the Fasci Italiani di Combattimento in 1919, which was the origin of fascism.

On both sides, large sums of money were raised for soldiers, their families, and the injured. The Nail Men were a German example. Across the British Empire, many patriotic funds were set up, including the Royal Patriotic Fund Corporation, Canadian Patriotic Fund, and Queensland Patriotic Fund.

Main articles: Opposition to World War I and 1917 French Army mutinies

Many countries jailed people who spoke out against the war, including Eugene Debs in the US and Bertrand Russell in Britain. In the US, the Espionage Act of 1917 and Sedition Act of 1918 made it a federal crime to oppose military recruitment or make statements seen as "disloyal." Some nationalists opposed the war too. Most Irish people agreed to take part in 1914 and 1915, but a small group of Irish nationalists strongly opposed it. Irish nationalists and Marxists wanted independence, which led to the Easter Rising in 1916. In response, the British government placed Ireland under martial law. Opposition to the war grew, leading to the Conscription Crisis of 1918.

Other opposition came from conscientious objectors, some socialist and some religious, who refused to fight. In Britain, 16,000 people asked for conscientious objector status. Some of them, including peace activist Stephen Hobhouse, also refused alternative service. They spent years in prison, some of it in solitary confinement.

In 1917, protests spread in Russia. On 1–4 May 1917, many workers and soldiers in Petrograd, and later in other Russian cities, marched led by the Bolsheviks. They carried banners reading "Down with the war!" This created a crisis for the Russian Provisional Government. In Milan, Bolshevik revolutionaries organised riots in May 1917 calling for an end to the war. The army entered the city with tanks and machine guns to face the Bolsheviks and anarchists, and took control on 23 May. Several people were killed and many were arrested.

Technology

See also: Technology during World War I

World War I began as a clash between modern technology and older tactics. This led to many people being hurt or killed. By the end of 1917, however, the major armies had updated their methods. They used the telephone, wireless communication, armoured cars, tanks (especially the test tank called Little Willie), and aircraft.

Both sides used several kinds of poison gas. It never became a decisive weapon, but it was one of the most feared weapons of the war.

Artillery also changed a lot. In 1914, cannons were placed at the front line and fired straight at their targets. By 1917, indirect fire was common. Guns, mortars, and even machine guns could hit targets they could not see. New ways of finding and aiming at targets were used, especially aircraft and the field telephone. Fixed-wing aircraft were first used for reconnaissance, which means looking at the enemy from above, and for ground attack. To shoot down enemy planes, anti-aircraft guns and fighter aircraft were developed. Strategic bombers were created, mainly by the Germans and British. The Germans also used Zeppelins. Near the end of the war, aircraft carriers were used for the first time. In 1918, HMS Furious launched Sopwith Camels in a raid on the Zeppelin hangars at Tønder.

Diplomacy

Main article: Diplomatic history of World War I

During the war, countries used talks and propaganda to gain friends and weaken their enemies. Their diplomacy mostly dealt with five issues. Countries used propaganda campaigns. They also set and changed their war goals, which became tougher as the war went on. They tried to bring neutral nations (Italy, the Ottoman Empire, Bulgaria, and Romania) to their side by offering them pieces of enemy land. The Allies also encouraged minority groups inside the Central Powers, especially Czechs, Poles, and Arabs, who wanted more independence.

Several countries, or leaders on each side, suggested peace. Neutral countries also offered to help make peace. None of these proposals got very far.

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. Burial grounds that began near the battlefields were later moved to formal graveyards. Groups such as the Commonwealth War Graves Commission, the American Battle Monuments Commission, the German War Graves Commission, and Le Souvenir français look after these graveyards. Many places also have monuments to the missing or unidentified dead, such as the Menin Gate Memorial to the Missing and the Thiepval Memorial to the Missing of the Somme. In 1915, John McCrae, a Canadian army doctor, wrote the poem In Flanders Fields to honour those who died in the war. It is still read today, especially on Remembrance Day and Memorial Day.

The National World War I Museum and Memorial in Kansas City, Missouri honours all Americans who served in the war. The Liberty Memorial was dedicated on 1 November 1921. The British government set aside many resources to remember the war from 2014 to 2018, in the commemoration of the war during the period 2014 to 2018, led by the Imperial War Museum. On 3 August 2014, French President François Hollande and German President Joachim Gauck marked the centenary of Germany's declaration of war on France by laying the first stone of a memorial at Vieil Armand. In German, this place is called Hartmannswillerkopf. The memorial honours French and German soldiers who died in the war. For the centenary of the 1918 Armistice, French President Emmanuel Macron and German Chancellor Angela Merkel visited the site where the Armistice of Compiègne was signed. They unveiled a plaque to reconciliation.

Main article: Historiography of World War I

Further information: Historiography of the causes of World War I

... "Strange, friend," I said, "Here is no cause to mourn." "None," said the other, "Save the undone years" ...

— Wilfred Owen, Strange Meeting, 1918

People have tried to understand the meaning and results of modern warfare since the war, and historians still study this today. Teaching World War I is hard. Compared with World War II, it is often seen as "a wrong war fought for the wrong reasons," without a clear story of good versus evil. Because it has no clear heroes or villains, it is often taught by theme, which can hide how complicated it was. Historian Heather Jones says that a cultural shift in the 21st century helped refresh the way historians study it. Scholars now ask new questions about military occupation, the radicalisation of politics, race, medical science, gender, and mental health. Historians have long debated why the war began, why the Allies won, whether generals were responsible for high casualty rates, how soldiers endured trench warfare, and how much the civilian home front supported the war effort.

Further information: Zone rouge and Iron harvest

As late as 2007, unexploded ordnance at battlefield sites such as Verdun and the Somme still posed a danger. In France and Belgium, people who find hidden weapons that did not explode get help from weapons disposal units. In some places, plant life has still not recovered from the war.