He married Millicent (or Maud) de Gournai (d.1260), a daughter of Hugh de Gournai and widow of
Amaury VI of Montfort-Évreux (d. 1213),
Earl of Gloucester. By his marriage he gained six and a half
fees in Oxfordshire. Millicent survived him and in 1255 was awarded the custody of Princess
Margaret, later Queen of Scots, daughter of King Henry III. By Millicent he had issue including: •
William III de Cantilupe (d.1254), eldest son and heir; • Hugh de Cantilupe (d.1285),
Archdeacon of Gloucester, 2nd son; one of the executors of the will of his uncle Bishop Walter de Cantilupe. •
Thomas de Cantilupe (1220-1282),
Bishop of Hereford and
Chancellor of England, canonised in 1320 as a saint. • Sir Nicholas de Cantilupe (d.1266), of
Greasley Castle in
Nottinghamshire, who married Eustachia FitzHugh, heiress of Greasley. His son was
William de Cantilupe, 1st Baron Cantilupe (1262-1308) of Greasley, summoned by writ to Parliament in 1299. • Juliana de Cantilupe, who at some time before 1245 married Robert de Tregoz (d.1268) of
Ewyas Harold in
Herefordshire, by whom she was the mother of
John de Tregoz, 1st Baron Tregoz, summoned by writ to Parliament in 1297. • Agnes de Cantilupe (d.post-1279), who married Robert St John (d.1266/7), grandparents of
John St John, 1st Baron St John (d. 1329) of Basing. Agnes survived her first husband, and before 1271 remarried to John de Turville. • 3rd daughter, name unknown, who married Robert de Gregonet. ==Death and succession==