Worcester, Thomas Percy, earl of (wŏsˈtər) [key], c.1344–1403, English nobleman; brother of Henry Percy, 1st earl of Northumberland. He served with considerable success in the wars in France and Spain, especially as admiral of the fleet of the north, a position to which he was appointed in 1378. He also served on several diplomatic missions, heading the English embassy to France to treat for peace in 1392. He was created earl of Worcester by Richard II in 1397. He accompanied Richard to Ireland in 1399 as admiral, but upon their return to England he joined his brother and his nephew, Sir Henry Percy, in supporting the seizure of the throne by Henry IV. Henry confirmed Worcester's past privileges and in 1401 appointed him seneschal (steward), lieutenant of South Wales, and tutor to the prince of Wales (1402). In July, 1403, Worcester surprised the king by joining his kinsmen in open revolt against the crown. Captured in the subsequent battle of Shrewsbury, Worcester was beheaded.