Mary of Lancaster, Baroness Percy

Mary of Lancaster, Baroness Percy, was born around 1320 or 1321, the youngest surviving child of Henry, 3rd Earl of Lancaster, and his wife Maud Chaworth. Through her father, she was a great-granddaughter of Henry III of England. Her siblings included Henry of Grosmont, 1st Duke of Lancaster; Maud, Countess of Ulster; Joan, Baroness de Mowbray; and Eleanor, Countess of Arundel. She was the aunt of Blanche of Lancaster, John of Gaunt’s first wife and mother to Henry IV of England. Mary married Henry Percy, eldest son of Henry de Percy, 2nd Baron Percy, and Idoine de Clifford in 1334 at Tutbury Castle. Her husband later became the 3rd Baron Percy. She died on 1 September 1362 in Alnwick, Northumberland, England.