Lord Boyce joined the Royal Navy in 1961, became a submariner and also a specialist in anti-submarine warfare, and commanded both submarines and surface ships. He had a number of Flag appointments, including NATO Commands, and rose to the position of First Sea Lord and Chief of the Naval Staff in 1998. He served as Chief of the Defence Staff and professional head of the Armed Forces - from February 2001, and on his retirement in the summer of 2003, he was created a Life Peer.

He became the first Colonel Commandant of the Special Boat Service in November 2003 and Deputy Lieutenant of Greater London in December 2003. He was appointed Lord Warden and Admiral of the Cinque Ports and Constable of Dover Castle in July 2004. He is currently on the Boards of WS Atkins plc and VT Group plc, and an advisor to CSC.