The Army Department Constabulary was a police force in the United Kingdom formed as a result of the Special Constables Act 1923. Originally, the Army used serving soldiers to guard its establishments and the only call for police was at places like the Royal Arsenal at Woolwich. A War Department Constabulary was formed in 1925, and was renamed Army Department Constabulary in 1964 when the War Office became the Army Department. The Ministry of Defence Police absorbed the ADC in 1971, along with the Air Force Department Constabulary and the Admiralty Constabulary.