time of ww1 By codydowns Jun 28, 1914 Archduke ferdinand is shot and killed Jul 3, 1914 Austria- hungary gets upset and threatens serbia Jul 30, 1914 Russia protects serbia Aug 24, 1914 Germany invades russia to help austria with the war Apr 22, 1915 Germany used gas for the first time04 May 7, 1915 The lusitania sinks making the americans upset Sep 18, 1915 Germany limits the submarine warfare Sep 15, 1916 The first tanks are deployed Feb 1, 1917 The germans restart the submarine warfare Feb 25, 1917 The americans get a telegram the germans sent to mexico