William de Warenne (1256–1286)
William married Joan, daughter of Robert de Vere, 5th Earl of Oxford. They had the following children:
- John de Warenne, 7th Earl of Surrey (June 1286 – June 1347)
- Alice de Warenne (15 June 1287 - 23 May 1338), wife of Edmund FitzAlan, 9th Earl of Arundel.
William was killed in a tournament at Croydon in 1286, predeceasing his father. It has been suggested that this was murder, planned in advance by William's enemies. On the 6th Earl's death the title went to John, the only son of William. John died without legitimate children, so on his death the title passed to Richard FitzAlan, 10th Earl of Arundel, eldest son of Edmund FitzAlan and John's sister Alice.
|Ancestors of William de Warenne (1256–1286)|
- Inquisition Post Mortem, dated 1286.
- Frederick Lewis Weis, Walter Lee Sheppard and William Ryland Beall, The Magna Charta Sureties, 1215: The Barons Named in the Magna Charta, 1215, and Some of Their Descendants who Settled in America During the Early Colonial Years (Genealogical Pub. Co., 1999), p. 184
- Juliet R. V. Barker, The Tournament in England, 1100-1400 (Boydell Press, 1986), p. 47
- The Chronicle of Bury St Edmunds, ed. A. Gransden (Nelson, 1964), p. 87
- From William's Oxford Inquisition Post Mortem taken on the Friday after Epiphany, 15 Edw. I: "John his son, born at the feast of the Nativity of St. John the Baptist, 14 Edw. I, is his next heir. " "Inquisitions Post Mortem, Edward I, File 47: 633. William de Warrenna. Inq. (Oxford). Friday after Epiphany, 15 Edw. I". Sharp, J.E.E.S, ed. (1906). Calendar of Inquisitions Post Mortem: Volume 2, Edward I. London: His Majesty's Stationery Office. p.382. Accessed via Internet Archive. Retrieved 17 June 2021.