CLIENT MAT
See the second edition of Cokayne's *Complete Peerage*, vol. XI, p. 95, note (h), referring to the summons of Robert (d. 1285), whom you are probably calling the first Baron, to Montfort's 1264 Parliament: "In 1616 the Barony was allowed precedence from this writ, a decision accepted by the Lords in 1806 ... ; but these writs, issued by Simon in the King's name, are no longer regarded as valid for the creation of peerages." The Ros Barony is now dated from the summons of William de Ros (d. 1316) in 1299.
Robert de Ros m. in the lifetime of his father, Isabel, dau. and heiress of William de Albini, feudal lord of Belvoir, in Leicestershire, by whom he acquired Belvoir Castle, co. Lincoln, and other extensive landed possessions. This great heiress was in ward to the king and a mandate upon her marriage, bearing date at Windsor, 17 May, 1244, was directed to Bernard de Savoy and Hugh Giffard, to deliver her to her husband, the said Robert: "but not," says Dugdale, "without a round composition, for it appears that both he and his wife, in the 32nd Henry III [1248], were debtors to the king in no less than the sum of £3,285 13s. 4d., and a palfrey; of which sum the king was then pleased to accept by 200 marks a year until it should all be paid." In the 42nd of the same reign [1258], he had two military summonses with his father to march against the Scotch and Welsh--but afterward rearing, with the other barons, the standard of revolt, he had a chief command at the battle of Lewes, so disastrous to the royalists; and to his custody in the castle of Hereford was especially committed the person of Prince Edward. He was at the same time summoned 24 December, 1264, as Baron de Ros, to the parliament then called in the king's name by the victorious lords. But the fortune of war changing at the subsequent battle of Evesham, his lands were all seized by the crown and held until redeemed by his lordship under the Dictum of Kenilworth. In two years after this he must, however, have regained somewhat of royal favour for he had then permission to raise a new embattled wall around the castle of Belvoir. He d. 16 June, 1285, leaving issue by the heiress of Belvoir, William, his successor;
Robert (Sir), knighted 1296; and Isabel, m. to Walter de Fauconberge. His lordship was s. by his elder son, William de Ros, 2nd Baron. [Sir Bernard Burke, Dormant, Abeyant, Forfeited and Extinct Peerages, Burke's Peerage, London, 1883, p. 458, Ros, or Roos, Barons Ros]