World War I Timeline from 1914 to 1918

Archduke Ferdinand and his wife Sophie
Archduke Ferdinand and his wife Sophie are pictured here, one hour before they would be shot and killed by Serb nationalist Gavrilo Princip as they drove through the streets of Sarajevo. Bettmann / Contributor / Getty Images

World War I (WWI) was sparked by the assassination of Archduke Franz Ferdinand in 1914 and ended with the Treaty of Versailles in 1919. Find out what happened in between these momentous events in this WWI timeline.

In a Tumultuous 1914, World War I Begins

  • July 28 - Austria-Hungary declares war on Serbia.
  • August 1 - Germany declares war on Russia.
  • August 3 - Germany declares war on France.
  • August 4 - The United Kingdom declares war on Germany, after Germany invades Belgium.
  • August 6 - Austria-Hungary declares war on Russia and Serbia declares war on Germany.
  • August 26 - The Battle of Tannenberg begins.
  • August 19 - U.S. President Woodrow Wilson announces the U.S. will remain neutral.
  • September 5 - The First Battle of the Marne begins. Trench warfare begins as soldiers on both sides dig in.
  • October 19 - Battle of Ypres begins.
  • November 3 - The United Kingdom announces that the North Sea is a military area, effectively creating a blockade of goods into Germany.
  • December 24 The unofficial Christmas truce is declared.

Key Events in 1915

  • February 4 - Germany declares a "war zone" around Great Britain, essentially effecting a submarine blockade where even neutral merchant vessels were to be potential targets.
  • February 19 - The Dardanelles Campaign begins.
  • April 22 - The Second Battle of Ypres begins. It is during this battle that the Germans first use poison gas.
  • April 25 - The Battle of Gallipoli begins.

    May 7 - The British ocean liner RMS Lusitania is sunk by German U-boat, U-20

  • September 5 - Tsar Nicholas II takes personal control over Russia's armies.

    Key Events in 1916

    • February 21 - The Battle of Verdun begins. The Battle of Verdun was the longest battle of World War I and was one of the bloodiest.
    • May 31 - The Battle of Jutland, the major naval battle of the war, begins.
    • July 1 - The Battle of the Somme begins. During the Battle of the Somme, tanks are first introduced into battle.

    Key 1917 Events

    • January 19 - Germany sends the secret Zimmerman Telegram to Mexico in an effort to entice Mexico to join the war. The British intercept and decipher the coded message.
    • March 15 - Russian Tsar Nicholas II abdicates.
    • April 6 - The United States declares war on Germany.

      July 31 - The Battle of Passchendaele (also known as the Third Battle of Ypres) begins.

    • November 7 - The Bolsheviks successfully overthrow the Russian government during the 1917 Russian Revolution.

    • December 17 - The armistice agreed upon between the new Russian government and the Central Powers goes into effect.

    1918 Key Events

    • January 8 - U.S. President Woodrow Wilson issues his Fourteen Points to peace.
    • March 3 - Russia signs the Treaty of Brest Litovsk, which is a peace treaty between Russia and the Central Powers.
    • March 21 - Germany launches the Spring Offensive.
    • April 21 - German flying ace Baron Manfred von Richthofen (more commonly known as the Red Baron), is shot down.
    • July 15 - The Second Battle of the Marne begins.
    • November 9 - German Kaiser Wilhelm II abdicates and flees Germany.
    • November 11 - Germany signs the armistice at Compiegne, France. Fighting ends on the 11th hour of the 11th day of the 11th month (i.e. 11 a.m. on November 11).

    World War I Draws to a Close in 1919