1914 - World War 1 Timeline
July 28: Austria-Hungary declares war on Serbia.
August 1: Germany declares war on Russia.
August 2: German troops occupy Luxembourg
August 3: Germany declares war on France
August 4: Germany invades neutral Belgium; the United Kingdom declares war on Germany in response.
August 10: Austria-Hungary declares war on Russia.
August 12: The United Kingdom and France declare war on Austria-Hungary.
August 14: Austrian and Serbian forces meet at Cer
August 19: Austrian forces defeated by Serbians at Cer
August 20: German forces occupy Brussels
August 23: Japan declares war on Germany
September: Unity Pact signed by France, Britain, and Russia
October 9: Siege of Antwerp — Antwerp, Belgium falls to German troops.
October 29: The Ottoman Empire enters the war on the side of Germany and Austria-Hungary.
November 2: Russia declares war on Turkey.
November 5: France and United Kingdom declare war on Turkey.
1915 - World War 1 Timeline
April 24: The events commonly referred to as the Armenian Genocide begin in the Ottoman Empire
April 25: Gallipoli campaign commences
April 26: Italy secretly signs the London Pact with the Triple Entente
May 23: Italy declares war on Austria-Hungary
October 14: Bulgaria declares war on Serbia and enters the war on the side of Germany and Austria-Hungary
1916 - World War 1 Timeline
March 9: Germany declares war on Portugal (see Portugal in the Great War)
August 27: Romania declares war on Austria-Hungary
August 28: Italy declares war on Germany
September 15: Battle of the Somme — two men die for every centimetre of land captured
1917 - World War 1 Timeline
February 24: United States ambassador to the United Kingdom Walter H. Page is given the Zimmermann Telegram, in which the German Empire offers to give the American Southwest back to Mexico if Mexico declares war on the United States
April 6: The United States declares war on Germany.
June 27: Greece...