• Russia Mobilizes

    Russia begins mobilizing its forces in defense of Serbia, escalating tensions
  • Britain Declares War on Germany

    Britain declares war on Germany in response to the invasion of Belgium
  • Assassination of Archduke Franz Ferdinand

    The heir to the Austro-Hungarian throne is assassinated by Gavrilo Princip in Sarajevo, triggering a chain reaction that leads to the war.
  • Austria-Hungary Declares War on Serbia

    Austria-Hungary declares war on Serbia, beginning the escalation of the conflict.
  • Germany Declares War on Russia

    In response to Russia’s mobilization, Germany declares war on Russia
  • Germany Declares War on France

    Germany declares war on France as part of its strategy to invade France via Belgium
  • Germany Invades Belgium

    Germany invades Belgium, violating its neutrality, prompting Britain to declare war on Germany
  • First Battle of the Marne

    Allied forces stop the German advance into France, marking a significant turning point early in the war (September 6–12, 1914)
  • The Battle of Ypres

    The first battle of Ypres takes place in Belgium, with heavy losses on both sides (October 19 – November 22, 1914)
  • Gallipoli Campaign

    Allied forces attempt to secure a route to Russia through the Dardanelles, but are defeated by the Ottoman Empire (April 25, 1915 – January 9, 1916)
  • The Battle of Verdun

    One of the longest and bloodiest battles of WWI, with over 700,000 casualties (February 21 – December 18, 1916).
  • The Battle of the Somme

    One of the largest battles of the war, with over one million casualties, it marks the first use of the tank in warfare (July 1 – November 18, 1916)
  • Russian Revolution

    The Russian Revolution leads to the overthrow of the Tsarist government and the rise of the Bolsheviks under Lenin (March through November 1917)
  • United States Enters the War

    The United States declares war on Germany following unrestricted submarine warfare and the Zimmermann Note
  • The Battle of Passchendaele

    Also known as the Third Battle of Ypres, it results in heavy casualties and gains little ground for either side (July 31 – November 10, 1917)
  • The Spring Offensive (March – July 1918)

    Germany launches a series of offensives on the Western Front in a last-ditch attempt to win the war
  • Russia Signs the Treaty of Brest-Litovsk

    Soviet Russia exits the war, signing a peace treaty with the Central Powers
  • Treaty of Versailles

    The peace treaty officially ends the war, placing heavy reparations and territorial losses on Germany
  • The Second Battle of the Marne

    The Allied forces, bolstered by American troops, successfully repelled the last German offensive (July 15 – August 5, 1918)
  • Armistice Signed

    An armistice is signed between Germany and the Allies, ending the fighting on the Western Front