Sir William Penn (23 April 1621 – 16 September 1670) was an English admiral, and the father of William Penn, founder of the colony of Pennsylvania. Penn was born in St. Thomas Parish, Bristol to Giles Penn and Joan Gilbert . On 6 June 1643 he married Margaret Jasper, a daughter of a famous and wealty Dutch merchant. They had three children: Margaret, Richard and William.
He served his apprenticeship at sea with his father. In the first Civil War he fought on the side of the parliament, and was in command of a ship in the squadron maintained against the king in the Irish seas. The service was arduous and called for both energy and good seamanship. In 1648 he was arrested and sent to London, but was soon released, and sent back as rear admiral in the Assurance. The exact cause of the arrest is unknown, but it may be presumed to have been that he was suspected of being in correspondence with the king's supporters. It is highly probable that he was, for until the Restoration he was regularly in communication with the Royalists, while serving the parliament, or Cromwell, so long as their service was profitable, and making no scruple of applying for grants of the confiscated lands of the king's Irish friends.
After 1650 he was employed in the Ocean, and in the Mediterranean in pursuit of the Royalists under Prince Rupert. He was so active on this service that when he returned home on the 18th of March 1651 he could boast that he had not put foot on shore for more than a year.
In 1654 he offered to carry the fleet over to the king, but in October of the same year he had no scruple in accepting the naval command in the expedition to the West Indies sent out by Cromwell. In 1655 he commanded the fleet that launched a bungled attack on La Hispaniola. He was not responsible for the shameful repulse at San Domingo, which was due to a panic among the troops. Afterwards the less desirable island of Jamaica was seized for the Commonwealth regime. On their return he and his military colleague Venables were sent to the Tower. He made humble submission, and when released retired to the estate he had received from confiscated land in Ireland.
He continued in communication with the Royalists, and in 1660 had a rather obscure share in the Restoration: he was sent in the Naseby (later the Royal Charles) to fetch king Charles II over to England.
The key source for the adult life of Penn is the Diary of his next door neighbour Samuel Pepys. In 1660 Penn was appointed a Commissioner of the Navy Board where he worked with Pepys, Clerk of the Acts to the Navy Board. The character of “mean fellow” given him by Pepys is borne out by much that is otherwise known of him. But it is no less certain that he was an excellent seaman and a good fighter.
Like Pepys and the Earl of Sandwich (Pepys' patron at the Navy Board) Penn was a "moderate" Roundhead who had succeeded in maintaining his position at the Restoration. Unsurprisingly, Penn appears several times in Pepys diary most vividly in an entry for 1665 when we read,
"At night home and up to the leads [roof], were contrary to expectation driven down again with a stinke by Sir W. Pen's shying of a shitten pot in their house of office"
A native of the West Country Sir William Penn is buried in the church of St. Mary Redcliffe in Bristol. His helm and half-armour are hung on the wall, together with the tattered banners of the Dutch ships that he captured in battle. His portrait by Lely is in the Painted Hall at Greenwich.
Though Sir William Penn was not a high-minded man, he is a figure of considerable importance in British naval history. As admiral and general for the parliament he helped in 1653 to draw up the first code of tactics provided for the navy. It was the base of the “Duke of York's Sailing and Fighting Instructions,” which continued for long to supply the orthodox tactical creed of the navy.