WW1 Timeline (1914-1918) By historystudent2018 Jun 28, 1914 Archduke Assasination Jul 30, 1914 Russia Mobilizes Apr 7, 1915 Lusitania Sink Apr 22, 1915 Germany Fires Sep 18, 1915 Germany Limits Submarines Sep 16, 1916 First Tanks Feb 1, 1917 Submarines back Feb 25, 1917 Zimmerman Telegram