The 9th (Service) Battalion landed in Gallipoli as part of the 39th Brigade in the 13th (Western) Division in July 1915; the battalion was evacuated to Egypt in January 1916 and then moved to Mesopotamia in February 1916. Elements of the 39th brigade formed Dunsterforce which fought against the Ottoman Empire at the Battle of Baku in August 1918. William Slim served with the battalion and was awarded the Military Cross in February 1918 for actions in Mesopotamia.