William de Ros, 3rd Baron Ros, was summoned to parliament from 20 November, 1317, to 12 September, 1342. This nobleman, in the 5th Edward II (1312), was one of the commissioners appointed to negotiate peace with Robert Bruce, King of Scotland, about which time he came to an agreement with the king regarding the castle of Werke, which he then exchanged with the crown for other lands. He was subsequently much engaged in the wars of Gascony and Scotland. His lordship m. Margery, elder sister and co-heir of Giles de Badlesmere, of Leeds Castle, in Kent, a great feudal baron, by whom he had issue, William, his heir; Thomas, who s. his brother; Margaret; Maud, m. to John, Lord Welles; Alice, m. Nicholas, Lord Meinell; and Milicent, m. to William, Lord d'Eyncourt. He d. 16 February, 1342-3, and was s. by his elder son, William de Ros, 4th Baron Ros. [Sir Bernard Burke, Dormant, Abeyant, Forfeited, and Extinct Peerages, Burke's Peerage, London, 1883, p. 459, Ros, or Roos, Barons Ros]