Battles of WWI By s-adhughes Jul 28, 1914 Austria-Hungary declares war on Serbia Aug 2, 1914 Germany invades Luxembourg Aug 3, 1914 Germany delcares war on France Aug 20, 1914 Battle of Morhange, Sarrenbourg Aug 21, 1914 Battle of Charleroi, Ardennes Aug 23, 1914 Battle of Mons Aug 23, 1914 Battle of Tanneberg, Lemberg, Krasnik Aug 24, 1914 Battle of Mortagne Sep 6, 1914 Battle on Drina Jan 18, 1915 Battle of Jassin May 4, 2017 Germany declares war on Russia