I. Robert de Willoughby, s. and h., b. circa 1250-60, had a protection, going to Scotland with his great-uncle, the Bishop of Durham, 12 June 1298; was often sum. against the Scots, 1300-15; and took part in the seige of Carlaverock, July 1300. He is said to have been granted the manor of Eresby afsd. by his grandfather, John Beke, in (1301-02) 30 Edw. I. He was sum. to Parl. from 26 July (1313) 7 Edw. II to 26 Nov. (1313) 7 Edw. II, by writs directed Roberto de Wylghby, whereby he is held to have become LORD WILLOUGHBY. On 16 Oct. 1313, as a follower of Thomas of Lancaster, he was pardoned for his activities against Gavaston. He m., in or before 1303, Margaret, da. of Edmund (Deincourt), 1st Lord Deincourt, by Isabel, da. of Sir Reynold de Mohun, of Dunster, Somerset. He d. shortly before 25 Mar. 1317. She d. shortly before 18 Oct. 1333.