The Bangladesh Army is the land forces branch and the largest of the three defence service of the Bangladesh Armed Forces. The primary mission of the Army is to provide necessary forces and capabilities in support of Bangladesh's security and defence strategies including defence of the nation's territorial integrity against external attack. Control and operations are administered by the Department of the Army of the Armed Forces Division. In addition to its primary mission the Bangladesh Army is also constitutionally obligated to assist the civilian government during times of national emergency. This role is commonly referred to as "aid to civil administration".