World War I

Also called

The First World War; the Great War^[1][2]

Dates

July 28, 1914, to Nov 11, 1918 (fighting); Treaty of Versailles signed June 28, 1919^[3]

Trigger

Assassination of Archduke Franz Ferdinand in Sarajevo, June 28, 1914^[3]

Allied powers

France, Britain, Russia, Serbia, Belgium, Japan, Italy from 1915, the United States from 1917, and others^[3][4]

Central Powers

Germany, Austria-Hungary, the Ottoman Empire, Bulgaria^[3]

Military deaths

About 8.5 to 9 million, depending on the count^[5][4][1]

Wounded

About 21 million^[5][4]

Total deaths

15 to 22 million, civilians included, in the range given by Wikipedia; a full accounting does not exist^[2][5]

World War I was a global conflict fought from 1914 to 1918 between the Allied powers and the Central Powers, in which more than 9 million soldiers died by one common count.^[4] It ended with the collapse of the Russian, German, Austro-Hungarian and Ottoman empires and the drawing of new borders across Europe and the Middle East.^[2]

Origins

On June 28, 1914, Gavrilo Princip shot Archduke Franz Ferdinand, heir to the Austro-Hungarian throne, and his wife Sophie in Sarajevo, and Vienna blamed Serbia.^[3][4] Kaiser Wilhelm II pledged German backing on July 5, a promise remembered as the blank check, and Austria-Hungary declared war on Serbia on July 28.^[4] Russia ordered general mobilization two days later in Serbia's support.^[2]

5:42 The crisis of summer 1914 From the Balkan wars and the assassination to the ultimatum to Serbia, and the allies each side drew in.

Alliance commitments then turned a Balkan crisis into a continental one within a week.^[4] Germany declared war on Russia and France, and its troops crossed into Belgium on Aug 4 as the Schlieffen Plan called for; Britain declared war on Germany the same day, which put its dominions such as Australia at war automatically.^[4][6] The Ottoman Empire joined the Central Powers late in the year, and Britain and France declared war on it on Nov 5.^[4][3]

Course of the war

The German drive came within 30 miles of Paris before the First Battle of the Marne stopped it in September 1914, ending hopes of a quick victory.^[4] The First Battle of Ypres then closed without a decision and marked the start of trench warfare, and a nearly unbroken line of trenches came to fix the Western Front.^[3][2] In the east, Germany and Austria-Hungary halted the Russian invasion at Tannenberg.^[4] The war also reached German colonies: French and British troops entered Togoland and Kamerun in August 1914, Japan seized Tsingtao and German Pacific territories, and fighting in German East Africa went on until after the armistice.^[2]

0:49 Trenches on every front Imperial War Museums: the trenches ran from France and Belgium to Gallipoli, Italy, the Middle East and Africa.

3:37 The football at the Christmas truce A veteran recalls a kickabout in no man's land in 1914: "it wasn't a team game in any sense of the word."

New weapons did not break the deadlock. Germany carried out the first successful gas attack in history at the Second Battle of Ypres, which began on April 22, 1915.^[3] Three days later British, French and ANZAC troops landed on the Gallipoli peninsula in a bid to knock out the Ottomans, a campaign that ended in Allied withdrawal.^[3][6] Italy joined the Allies that May.^[3]

6:48 Barrages, gas and tanks Imperial War Museums on the means tried against the trenches, and how little the first tanks did.

The year 1916 was the costliest of the stalemate. At Verdun, from Feb 21 to December, French and German forces together suffered close to a million casualties.^[3][4] Britain lost more than 57,000 men as casualties on July 1, the first day of the Somme, a battle that went on until November.^[4] The British fielded tanks for the first time at Flers-Courcelette on Sept 15, though only 15 of the 49 managed to move into no man's land.^[7] At sea, Jutland, on May 31, was the largest naval battle of the war and left no clear winner; the German fleet mostly stayed in port afterward, while a British blockade cut Germany's supplies.^[3][2] Russia's Brusilov offensive that June succeeded against Austria-Hungary, but it badly weakened both armies.^[2]

1917: revolution and American entry

Germany's decision to resume unrestricted submarine warfare from Feb 1, 1917, led the United States, neutral until then, to break diplomatic relations two days later.^[8] The sinking of the Lusitania on May 7, 1915, had killed 128 Americans and hardened public opinion, and British intelligence had intercepted the Zimmermann telegram, in which Germany offered Mexico an alliance.^[9][8] President Woodrow Wilson asked Congress for war on April 2, the Senate agreed 82 to 6, and the House followed 373 to 50 on April 6.^[9]

3:13 The Zimmermann Telegram A British decrypt that helped bring the United States into the war on April 6, 1917.

Russia moved the other way. Revolution ended czarist rule, the Bolsheviks seized power that autumn, an armistice followed in December, and the Treaty of Brest-Litovsk took Russia out of the war on March 3, 1918.^[4][3] In the Middle East, Britain and France had secretly divided the region in the Sykes-Picot Agreement of 1916, an Arab revolt rose against Ottoman rule, and Britain issued the Balfour Declaration on Nov 2, 1917, and captured Jerusalem that December.^[3]

The home fronts

The war reached civilians early. German zeppelin raids on Britain began in January 1915, and in February Germany declared waters around Britain open to submarine attack, making neutral merchant ships targets as well.^[3] About 20,000 French women and girls were deported from cities such as Lille for forced farm labor in April 1916.^[3] Governments also took new powers over their own people: the United States passed the Selective Service Act, its first draft since the Civil War, on May 18, 1917, and the Espionage Act on June 15.^[3] In Australia, two referendums on conscription failed and deepened social division, and many German-Australians were interned.^[6]

Victory and armistice

Freed in the east, Germany launched a spring offensive in the west in March 1918.^[2] It failed. The Allied Hundred Days Offensive, opening in August, broke the German line, and American troops fought their largest offensive at Meuse-Argonne from Sept 26.^[2][3] The Ottomans sought terms on Oct 30, Italy's victory at Vittorio Veneto ended the war on that front, and Austria-Hungary reached an armistice on Nov 4.^[6][3][4] Wilhelm II abdicated on Nov 9, and Germany signed an armistice that stopped the fighting on the Western Front at 11 a.m. Paris time on Nov 11.^[3]

7:35 Breaking the deadlock at Amiens In August 1918 the Allies advanced 11 km on a 24 km front: Ludendorff's "black day of the German army."

Human cost

Counts vary because no complete record exists. Britannica's table lists about 8.5 million military dead and 21 million wounded, and warns that a fully accurate tally may never be compiled.^[5] The National WWI Museum and Memorial uses 9 million in its memorial, with one poppy for every 1,000 deaths.^[1] Civilian estimates differ far more: History.com gives close to 10 million and Britannica about 13 million, and Wikipedia's range for all deaths is 15 to 22 million.^[4][5][2]

Empires drew heavily on their subjects. An estimated 1.3 million Indian soldiers and laborers served, and Australia, with fewer than five million people, enlisted 416,809 men, of whom more than 60,000 died.^[2][6]

In the Ottoman Empire, at least 664,000 and possibly as many as 1.2 million Armenians died between spring 1915 and autumn 1916, according to the United States Holocaust Memorial Museum, which describes the events as genocide.^[10] U.S. President Joe Biden recognized them as genocide on April 24, 2021.^[11] Turkey acknowledges Armenian deaths in the war but rejects the term, and its foreign ministry said the statement lacked a scholarly and legal basis.^[11]

As the war closed, an influenza pandemic killed at least 50 million people worldwide, according to the U.S. Centers for Disease Control and Prevention, and about 675,000 in the United States.^[12] The disease spread through the trenches and was a major killer on both sides.^[2]

Peace and consequences

The Paris Peace Conference opened in January 1919, dominated by Britain, France, the United States and Italy; the defeated powers were excluded, and Bolshevik Russia was not invited.^[13] Under the Treaty of Versailles, signed on June 28, 1919, Germany lost about 10% of its prewar European territory and all its overseas possessions, accepted responsibility for the war, limited its military and agreed to pay reparations, which were set in 1921 at 132 billion gold marks.^[13]

The treaty also created the plan for a League of Nations, which Wilson championed. The U.S. Senate rejected it, falling seven votes short on March 19, 1920, and the United States never joined; it made a separate peace with Germany on Aug 25, 1921.^[13] The Treaty of Sèvres of Aug 10, 1920, began the partition of the Ottoman lands.^[3]

New states emerged from the wreck of the old empires, including Poland, Finland, the Baltic states, Czechoslovakia and Yugoslavia.^[2] A second and deadlier global conflict, World War II, followed two decades later.^[2]

Timeline

1. 1914-06-28 Archduke Franz Ferdinand is assassinated in Sarajevo.^[3]
2. 1914-07-28 Austria-Hungary declares war on Serbia.^[3]
3. 1914-08-04 German troops enter Belgium; Britain declares war on Germany.^[4][6]
4. 1915-04-22 The Second Battle of Ypres opens, with the first successful gas attack.^[3]
5. 1915-04-25 Allied troops land at Gallipoli.^[3]
6. 1916-02-21 The Battle of Verdun begins.^[3]
7. 1916-07-01 The Battle of the Somme begins.^[3]
8. 1917-04-06 The United States enters the war.^[3]
9. 1918-03-03 Russia leaves the war by the Treaty of Brest-Litovsk.^[3]
10. 1918-11-11 Germany signs the armistice and fighting stops on the Western Front.^[3]
11. 1919-06-28 The Treaty of Versailles is signed.^[3]