By 1918, the original armies had been so badly reduced that the Empire was forced to establish new unit definitions which incorporated these armies. These were the Eastern Army Group and Yildirim Army Group. However, although the number of armies was increasing over the four years of the war, the Empire's resources of manpower and supplies were declining, so that the Army Groups in 1918 were smaller than the armies of 1914. The Ottoman Army was still partially effective until the end of the war.