1621–70, British admiral. In the English civil war he served in Parliament's naval forces, and he joined the pursuit (1651–52) of Prince Rupert in the Mediterranean. He served in the first Dutch War and in 1654 was made commander of the fleet that sailed for the West Indies and captured Jamaica (1655). He was arrested shortly after his return to England and imprisoned briefly before being allowed to retire to his Irish estates. The reason for his disgrace has never been definitely established. It probably had nothing to do with his secret negotiations with the exiled Charles II, who, when restored to the throne, knighted Penn (1660) and made him a commissioner of the navy. In the second Dutch War Penn was second in command to the duke of York (later James II) in the action of the fleet in 1665 and retired to shore duty when the duke was relieved of command. Penn's son was William Penn, founder of Pennsylvania.

Bibliography

See G. Penn, Memorials...of Sir William Penn (1833).