Battles of WWI By codie.goodman2008 Period: Aug 1, 1914 to Aug 30, 1914 Battle of Tannenberg Period: Sep 6, 1914 to Sep 12, 1914 First Battle of the Marne Period: Apr 25, 1915 to Jan 9, 1916 Battle of Gallipoli Period: May 22, 1915 to May 25, 1915 Second Battle of Ypres