Donald Henry Rumsfeld (born July 9, 1932) is currently serving as the 21st United States Secretary of Defense, since January 20, 2001, under President George W. Bush. He is the oldest person to have held that position, and was also the youngest when he served as the 13th Secretary of Defense from 1975 to 1977 under President Gerald Ford. Rumsfeld also served in various positions under President Richard Nixon, as well as four terms in the United States House of Representatives, and as U.S. ambassador to the North Atlantic Treaty Organisation (NATO) (1973-1974).
He served in the U.S. Navy from 1954 to 1957 as an aviator and flight instructor, training in North American SNJ basic trainers and later flying Grumman F6F Hellcat fighters. In 1957, he transferred to the Ready Reserve and continued his Naval service in flying and administrative assignments as a drilling reservist until 1975. He transferred to the Standby Reserve when he became Secretary of Defense in 1975 and to the Retired Reserve with the rank of Navy Captain in 1989.
He has also served as an official in numerous federal commissions and councils.
Rumsfeld married the former Joyce Pierson in 1954. They have three children and six grandchildren.