After retiring from the Royal Navy he pursued a career in politics and later became a Member of Parliament.

[1] Henry Killgrew entered the navy in 1666 at the rank of Lieutenant assigned to HMS Cambridge.

[2] He was promoted to Captain on 9 January 1671 and took command of HMS Forester (1657) and took part at the Battle of Solebay.

[2] In June 1689 Killgrew was promoted Vice-Admiral of the Blue as flag officer of HMS Kent.

On 17 February 1690 he advanced to Vice-Admiral of the Red and in May 1690 he was given command of the second rate HMS Duke.