King Henry I confirmed the Barony of Graystock unto Phorne, son of the said Lyulphe, whose posterity took their surname from the place, and were called de Greystock. Phorne was s. by his son Ivo. [Sir Bernard Burke, Dormant and Extinct Peerages, Burke's Peerage, Ltd, London, 1883, p. 254, Greystock, Barons Greystock]