THE WORLD ATLAS

War · 28 July 1914 – 11 November 1918

First World War

The First World War began a month after the assassination of Archduke Franz Ferdinand in Sarajevo on 28 June 1914. Austria-Hungary declared war on Serbia, and within days the alliance system drew in the great powers.

Germany and Austria-Hungary, joined by the Ottoman Empire in 1914 and Bulgaria in 1915, formed the Central Powers. Serbia, Russia, France, Belgium and the British Empire formed the Allies, or Entente, joined by Japan (1914), Italy (1915), Portugal and Romania (1916), and the United States, Greece, Siam, China and Brazil (1917). After the Marne the Western Front froze into trench warfare, while fighting spread to Eastern Europe, the Alps, the Balkans, the Middle East, Africa, East Asia and the oceans. Revolution took Russia out of the war in 1917–18. Germany's spring offensive of 1918 failed, Allied counter-offensives followed, and the Central Powers signed armistices between September and 11 November 1918. Four empires collapsed, and the peace treaties redrew the map of Europe and the Middle East.

Watch the war on the map

Dates
28 July 1914 – 11 November 1918
Casualties
An estimated 15 to 22 million soldiers and civilians died, with many millions more wounded.

The sides

Allies (Entente)

Central Powers

Timeline of the First World War

  1. Archduke Franz Ferdinand assassinated in Sarajevo

    Bosnia had been annexed by Austria-Hungary in 1908, angering Serbian nationalists. On 28 June 1914 Gavrilo Princip, a Bosnian Serb student, shot the heir to the Habsburg throne and his wife in Sarajevo. Austria-Hungary blamed Serbia and, assured of German backing, sent Belgrade an ultimatum it expected to be refused. The crisis of July 1914 turned a regional quarrel into a confrontation between Europe's two armed alliance blocs.

  2. Austria-Hungary declares war on Serbia

    Serbia accepted most of the ultimatum but not all of it, and on 28 July Austria-Hungary declared war. Russia mobilised in support of Serbia; Germany declared war on Russia on 1 August and on France on 3 August. Mobilisation timetables and alliance commitments meant that a Balkan war became a continental one in under a week, before diplomacy could slow it down.

  3. Germany invades Belgium; Britain declares war

    Germany's war plan aimed to knock out France quickly by swinging through neutral Belgium before turning east against Russia. German troops crossed the Belgian border on 4 August and besieged the fortresses of Liège. Britain, a guarantor of Belgian neutrality under the 1839 treaty, declared war on Germany the same day, bringing in its whole empire, including India, the dominions and its African colonies.

  4. Germany crushes a Russian army at Tannenberg

    Russia attacked East Prussia sooner than Germany expected, forcing it to move troops east. Between 23 and 30 August German forces under Hindenburg and Ludendorff encircled and destroyed the Russian Second Army near Tannenberg, taking a very large number of prisoners. Russia was driven out of East Prussia, but its offensive had drawn German strength away from France at a critical moment.

  5. The First Battle of the Marne halts the German advance

    German armies sweeping through Belgium and northern France came within reach of Paris by early September. From 5 to 12 September French and British forces counter-attacked along the River Marne, opening a gap between German armies and forcing them to retreat to the Aisne. The quick victory Germany had planned was lost; both sides dug in, and trenches soon ran from the Channel coast to Switzerland.

  6. Ottoman warships raid Russia's Black Sea ports

    The Ottoman Empire had signed a secret alliance with Germany in August. On 29 October Ottoman warships, led by two ex-German cruisers, shelled Russian ports on the Black Sea. Russia declared war on 1 November and Britain and France followed. Ottoman entry closed the Straits to Allied supplies for Russia and opened new fronts in the Caucasus, Mesopotamia, Sinai and Palestine.

  7. Japan captures Germany's Chinese base at Tsingtao

    Japan, allied to Britain since 1902, declared war on Germany on 23 August 1914 and moved against German possessions in Asia and the Pacific. Japanese forces, with a smaller British contingent, besieged the German naval base at Tsingtao on China's Shandong peninsula, which fell on 7 November. Japan also took Germany's island colonies north of the equator, extending its reach in East Asia.

  8. Germany uses poison gas on a large scale at Ypres

    On the Western Front neither side could break the trench lines. At the start of the Second Battle of Ypres, on 22 April 1915, German troops released chlorine gas against French and Algerian positions, opening a gap they could not exploit. Both sides went on to use chemical weapons throughout the war, and gas became one of the conflict's most feared features.

  9. Armenian deportations and massacres begin

    On the night of 23–24 April 1915 Ottoman authorities arrested hundreds of Armenian community leaders in Constantinople. Deportations of Armenians from Anatolia followed, with death marches towards the Syrian desert and mass killings. Estimates of the dead range from about 600,000 to 1.5 million. Almost all historians outside Turkey describe these events as genocide; the Turkish government rejects that term.

  10. Allied landings at Gallipoli

    Britain and France hoped to force the Dardanelles, take Constantinople and open a sea route to Russia. After a naval attack failed, British, French, Australian, New Zealand and Indian troops landed on the Gallipoli peninsula on 25 April 1915. Ottoman forces held the heights, and months of costly fighting followed. The Allies abandoned the campaign and withdrew their last troops in December 1915 and January 1916.

  11. A German U-boat sinks the liner Lusitania

    Germany had declared the waters around Britain a war zone in February 1915, using submarines against merchant shipping. On 7 May a U-boat torpedoed the British liner Lusitania off southern Ireland, killing more than a thousand passengers and crew, among them over a hundred Americans. The sinking turned American opinion against Germany, which for a time restricted submarine attacks to avoid war with the United States.

  12. Italy declares war on Austria-Hungary

    Italy had stayed neutral in 1914 despite its prewar alliance with Germany and Austria-Hungary. After the Allies secretly promised it Austrian territory, Italy declared war on Austria-Hungary on 23 May 1915, though not on Germany until August 1916. A new front opened along the Alps and the Isonzo River, where repeated Italian offensives over the next two years gained little ground at great cost.

  13. Bulgaria joins the Central Powers; Serbia is overrun

    Bulgaria, seeking territory lost in the Balkan Wars, declared war on Serbia on 14 October 1915. Attacked by German and Austro-Hungarian armies from the north and Bulgarians from the east, Serbia was conquered in little more than a month. Its army retreated across the Albanian mountains to the Adriatic coast and was evacuated by Allied ships, later fighting again on the Salonika front.

  14. The Battle of Verdun begins

    Germany attacked the fortress city of Verdun on 21 February 1916, aiming to wear down the French army in a battle France could not refuse. The fighting lasted until 18 December, when French counter-attacks had retaken most of the lost ground. Combined French and German casualties are estimated at roughly 700,000 to 975,000, and Verdun became a symbol of the war's attrition.

  15. Britain and Germany fight the naval Battle of Jutland

    Britain's Royal Navy blockaded Germany, and the German High Seas Fleet hoped to destroy part of the British Grand Fleet. The two fleets met in the North Sea off Denmark on 31 May and 1 June 1916, the war's largest naval battle. Britain lost more ships and men, but the German fleet returned to port and did not seek another major fleet action, so the blockade held.

  16. Russia's Brusilov Offensive breaks the Austro-Hungarian line

    To relieve pressure on France and Italy, Russian armies under General Aleksei Brusilov attacked along a wide front in Galicia and Volhynia on 4 June 1916. Short, surprise bombardments broke the Austro-Hungarian lines, and huge numbers of prisoners were taken. Germany had to send reinforcements east, and the offensive's early success encouraged Romania to join the Allies, but Russian losses were also very heavy.

  17. Sharif Hussein launches the Arab Revolt at Mecca

    Britain had promised in letters to Sharif Hussein of Mecca to support Arab independence in return for a rising against the Ottomans. On 10 June 1916 his forces attacked the Ottoman garrison at Mecca. Backed by British gold, weapons and officers such as T. E. Lawrence, Arab forces under his son Faisal took Aqaba in July 1917 and reached Damascus at the end of September 1918.

  18. The Battle of the Somme begins

    Britain and France attacked along the River Somme on 1 July 1916, partly to relieve Verdun. On the first day the British army suffered about 57,500 casualties, including some 19,200 dead, the worst single day in its history. The battle lasted until 18 November and gained only a few miles; British, French and German losses together exceeded a million, and tanks made their first appearance there.

  19. Romania enters the war on the Allied side

    Encouraged by the Brusilov Offensive and promised Austro-Hungarian Transylvania, Romania declared war and began hostilities against Austria-Hungary on 27 August 1916. German, Austro-Hungarian, Bulgarian and Ottoman forces counter-attacked from two sides, and Bucharest fell on 6 December. Romania's government and army held on in Moldavia but, isolated after Russia's collapse, signed a separate peace in May 1918, then re-entered the war on 10 November 1918.

  20. Revolution in Petrograd forces the Tsar to abdicate

    War losses, food shortages and distrust of the government fuelled protests in Petrograd from 8 March 1917 (February in Russia's old calendar). Troops joined the crowds, and Tsar Nicholas II abdicated on 15 March. A Provisional Government kept Russia in the war, but its 1917 summer offensive failed and the army began to disintegrate, while soviets of workers and soldiers competed for power.

  21. The United States declares war on Germany

    Germany resumed unrestricted submarine warfare on 1 February 1917, gambling that it could starve Britain before American forces arrived. The intercepted Zimmermann telegram, in which Germany proposed an alliance with Mexico, further angered American opinion. The United States declared war on Germany on 6 April 1917 as an 'associated power', and its troops reached the Western Front in growing numbers through 1918.

  22. Austro-German breakthrough at Caporetto

    On 24 October 1917 Austro-Hungarian and German divisions, using gas and infiltration tactics, broke the Italian line at Caporetto on the Isonzo. The Italian army fell back to the Piave River, losing very large numbers of men, many of them as prisoners. Britain and France rushed divisions to Italy, General Cadorna was replaced as commander, and the new line on the Piave held through the winter and against a final Austro-Hungarian offensive in June 1918.

  23. The Bolsheviks seize power in Russia

    Led by Lenin, the Bolsheviks overthrew the Provisional Government in Petrograd on 7 November 1917 (25 October in the old calendar), promising peace, land and bread. The new government agreed an armistice with the Central Powers on 15 December. Peace talks opened at Brest-Litovsk. Russia's withdrawal let Germany move many divisions to the Western Front for a final offensive, while Russia itself slid into a long civil war between the Bolsheviks and their opponents.

  24. British forces enter Jerusalem

    After failing twice at Gaza, the British Egyptian Expeditionary Force under General Allenby broke through the Ottoman line at Beersheba and Gaza in autumn 1917. On 11 December Allenby entered Jerusalem on foot. British troops had also taken Baghdad in March, and the Balfour Declaration of 2 November had promised support for a Jewish national home in Palestine, shaping the region's postwar history.

  25. Russia makes peace at Brest-Litovsk

    Soviet Russia signed the Treaty of Brest-Litovsk with Germany, Austria-Hungary, the Ottoman Empire and Bulgaria on 3 March 1918. Russia gave up Finland, the Baltic lands, Poland, most of Belarus and Ukraine, and Kars, Ardahan and Batum in the Caucasus. German troops occupied much of this territory, though Germany still kept large forces in the East. The treaty ended the Eastern Front for the Central Powers and was annulled after Germany's defeat in November 1918.

  26. Germany launches its Spring Offensive in the West

    With divisions freed from Russia, Germany tried to win in the West before American strength could tell. Operation Michael began on 21 March 1918 near Saint-Quentin and drove the British back many miles; further offensives followed into July, reaching the Marne again. The attacks gained ground but cost Germany its best troops and failed to break the Allied armies, now under a single commander, Ferdinand Foch.

  27. Allied victory at Amiens opens the Hundred Days Offensive

    After stopping the last German attack on the Marne in July, the Allies struck back. On 8 August British, Australian, Canadian and French forces attacked east of Amiens with tanks, aircraft and artillery and advanced several miles in a day. A series of Allied offensives followed, including the American-led Meuse–Argonne offensive from 26 September, pushing German armies back towards their own border.

  28. Allenby routs the Ottoman armies at Megiddo

    In Palestine, British Empire forces under Allenby, with Arab Revolt forces on their flank, attacked the Ottoman line on 19 September 1918. Cavalry broke through and the Ottoman armies in Palestine collapsed within days. Damascus was reached at the end of September, and the Ottoman Empire signed the Armistice of Mudros on 30 October, after Bulgaria had already signed an armistice on 29–30 September.

  29. Austria-Hungary signs an armistice after Vittorio Veneto

    Italy launched its offensive at Vittorio Veneto on 24 October 1918 as Austria-Hungary was breaking up into national states. The Austro-Hungarian army disintegrated, and on 3 November an armistice was signed at Villa Giusti near Padua, taking effect the next day. The Habsburg monarchy dissolved within days, as Czechoslovakia, Hungary and the new South Slav state went their own ways. Germany was now the only Central Power still fighting.

  30. Germany signs the armistice at Compiègne

    With its allies gone, its armies in retreat and revolution spreading at home, Germany sought terms. Kaiser Wilhelm II abdicated on 9 November, and German delegates signed the armistice in a railway carriage in the forest of Compiègne early on 11 November; fighting stopped at 11 a.m. The peace treaties followed, including the Treaty of Versailles with Germany on 28 June 1919.

Related

Other wars of the time

Sources