Dennis Callaghan from Sheffield joined Halifax Borough Police Force in 1939 and served at Warley Road Police Station, Halifax. Volunteered for the Commandos. Enlisted in General Service Corps 23 July 1942 and taken on strength 2nd Police Intake, Commando Depot (Commando Basic Training Centre), Achnacarry. Posted No.2 Commando 24 September 1942. Embarked for Gibraltar 11 April 1943.

Private Callaghan, No.2 Commando 6 Troop, was wounded in action 13 September 1943 at Salerno. The following year he was admitted to 2 Field Hospital, Central Meditteranean Force 23 June 1944. Discharged to No.2 Commando 4 July 1944. Appointed Lance Corporal on 11 September 1944. Admitted 98 General Hosital for 6 days from 24 October 1944. Attended No.34 Parachute Training Course at 4 P.T.S. 11-20 December 1944. Result Passed.

24 March 1945 promoted Acting Corporal.  Embarked for UK 19 June 1945. Released Class W (T) Reserve 5 October 1945.

Post war re-joined the Police Force. Promoted Police Sergeant in 1952 and served in the Criminal Investigation Department. In 1964 he retired from the Police after 25 years to take up employment selling insurance with the Australian Provident Society, Leeds. He retired in 1974 moving to Tenerife with his family where he died in 1987.