William Griffith

William Griffith (1480–1545) of Penrhyn Castle was a Welsh politician. He was knighted at the Siege of Tournai in 1513 and was Chamberlain of North Wales in 1520. He was with Henry VIII of England at the Sieges of Boulogne (1544–46). As a result, his father was close to the House of Grey, and became a member of King Edward IV's council. He was also knighted by Arthur Tudor, Prince of Wales.

His grandmother was Margaret Stanley, daughter of Lord Thomas Stanley, who became King of Mann and Lord Chamberlain, and his grandaunt was Lady Margaret Beaufort, mother of the first Tudor monarch, Henry VII. Griffith's mother-in-law remarried to Sir Rhys ap Thomas of Dinefwr, whose son, Griffith ap Rhys, was a companion at court. and a daughter, Margaret Griffith, who married Simon Thelwall.

William Griffith's great-great-grandmother was Morfydd, granddaughter of Tudur ap Goronwy, member of the Tudors of Penmynydd. Their family were allies and kinsmen of Prince Owain Glyndwr and Lord Tudur ap Gruffudd, of the Royal House of Mathrafal, during the Welsh war of independence.