Who Was When
Wars

World War I

See this year on the world timeline

Sides

Allies (Entente)

France, United Kingdom, Russian Empire (until 1917), Kingdom of Serbia, Kingdom of Italy (from 1915), and United States

against
Central Powers

German Empire, Austria-Hungary, Ottoman Empire, and Kingdom of Bulgaria (from 1915)

Countries today: Austria, Bulgaria, Germany, Hungary, Italy, Russia, Serbia, and Türkiye

What happened

On 28 June 1914 Gavrilo Princip, a Bosnian Serb, shot dead Archduke Franz Ferdinand, heir to the Austro-Hungarian throne, in Sarajevo. Austria-Hungary declared war on Serbia on 28 July, and within a week the alliances had drawn in Germany, Russia, France and Britain; German troops crossed neutral Belgium on their way into France. The Central Powers (Germany, Austria-Hungary, the Ottoman Empire and Bulgaria) fought the Allies: France, the British Empire with its dominions and India, Russia, Serbia, Belgium and Japan, joined later by Italy, Romania, the United States and others. After the Marne in September 1914 the Western Front settled into trench warfare, and battles such as Verdun and the Somme killed hundreds of thousands without breaking it; Germany released chlorine gas at Ypres in April 1915. Russia left the war after its 1917 revolutions and signed the Treaty of Brest-Litovsk in March 1918. With American troops arriving, the Allies stopped Germany's 1918 offensives and broke the Hindenburg Line; Germany's allies gave up one by one, and Germany signed an armistice on 11 November 1918.

Outcome: The Allies won: Germany signed an armistice on 11 November 1918 and the Treaty of Versailles in 1919, and the German, Austro-Hungarian, Russian and Ottoman empires broke up.

Key events

Leaders

  • Georges Clemenceau · Prime Minister of France from 1917 · Allies (Entente)
  • Ferdinand Foch · Supreme commander of the Allied armies in 1918 · Allies (Entente)
  • David Lloyd George · Prime Minister of the United Kingdom from 1916 · Allies (Entente)
  • Nicholas II · Emperor of Russia until 1917 · Allies (Entente)
  • Woodrow Wilson · President of the United States · Allies (Entente)
  • Wilhelm II · German Emperor · Central Powers
  • Paul von Hindenburg · Chief of the German General Staff from 1916 · Central Powers
  • Franz Joseph I · Emperor of Austria and King of Hungary until his death in 1916 · Central Powers
  • Enver Pasha · Ottoman minister of war · Central Powers

Deaths

Death tolls are estimates and often contested. Each is a range from its sources; a figure one party gives is marked as theirs.

Military deaths · All sides

Sources