1917

February 1 - Unrestricted submarine warfare declared by Germany, again. 
February 24 - The Sinking of the Laconia. 
March 15 - Tsar Nicholas abdicates. 
March-September - Russia collapses. 
April 6 - United States declares war on Germany. 
April 16-29 - Chemin des Dames Offensive. 
April - Battle of Arras & Vimy Ridge. 
April - Nivelle Offensive. 
June - Battle of Messines. 
July 6 - Aquaba captured by Arabs led by T.E.Lawrence. 
July 16-November 10 - Third Battle of Ypres. 
August 6 - Aleksander Fyodorovich Kerensky appointed Prime Minister of Russia. 
October - Battle of Caporetto. 
November 7 - Kerensky's government overthrown by Bolsheviks. 
November 10 - British reach Passchendaele. 
November - Battle of Cambrai. 
December 3 - German-Russian armistice. 
December 9 - Jerusalem captured by British.