Admiralty, in British government, department in charge of the operations of the Royal Navy until 1964. Originally established under Henry VIII, it was reorganized under Charles II. Five lords commissioners composed the board of Admiralty, each gradually developing his own field of specific responsibility, with the first lord responsible to Parliament. In 1832 it absorbed the navy board, previously responsible for the administrative organization. In 1964 the Admiralty became the navy department, coequal with the other service departments, of the ministry of defense. The navy is now directed by the Admiralty Board of the Defense Council, which consists of 4 naval and 7 civilian members, including the secretary of state for defense, who serves as chair.