WWI By CrimsonGamer Jul 28, 1914 WWI Begins Period: Jul 28, 1914 to Nov 11, 1918 WWI Aug 22, 1914 The Battle of Frontiers Aug 23, 1914 Battle Of Tannenberg May 23, 1915 Italy Joins WWI Feb 21, 1916 Battle Of Verdun Jul 31, 1917 Third Battle of Ypres Nov 11, 1918 WWI Is Over