1914

June 28 - Archduke Franz Ferdinand assassinated in Sarajevo. 
July 28 - Austria-Hungary declares war on Russia. 
August 1 - Germany declares war on Russia. 
August 3 - Germany declares war on France. 
August 4 - Great Britain declares war on Germany. 
August 4 - Germany invades neutral Belgium. 
August 26-30 - Battle of Tannenberg. 

August - Battle of Togoland. 

August - The Pursuit of the Goeben and the Breslau. 
September - First Battle of Aisne. 
September - Battle of Lemberg. 
September 5-10 - First Battle of the Marne. 
October-November - First Battle of Ypres. 
November - Battle of Lodz. 
December 25 - Unofficial Christmas Truce on the Western Front.