He was ambushed and slain after attending a tournament at Croydon. 1
Inquisition Post Mortem
633. William de Warrenna
Writ, 15 Dec. 15 Edw. I. 
[Oxford.] Inq. Friday after Epiphany, 15 Edw. I.
Croumers. The manor (extent given) of which the said William and Joan his wife were jointly enfeoffed by Sir Robert de Veer, earl of Oxford, father of the said Joan, to be held of Sir William de Valencia for the service of 1 knight's fee.
John his son, born at the feast of the Nativity of St. John the Baptist, 14 Edw. I, is his next heir.
[Norfolk.] Extent, Thursday before St. Matthias the Apostle, 15 Edw. I.
Boston. The manor (extent given) including herbage in Godwynescarwe, wreck of the sea, and the advowson of the church, which Robert de Veer, earl of Oxford, gave to the said William with Joan his daughter in free marriage, held of the said earl in chief for homage and service, doing 20s. yearly for the guard of the castle of Dover, and at the queen's hundred (court) of Northorpingham one suit.
He died on Sunday before St. Lucy in the said year.
Heir as above.
Buckingham. Extent, Wednesday before SS. Fabian and Sebastian, 15 Edw. I.
Medmenham. The manor (extent given) held of the earl of Oxford by service of 1 knight's fee, and it is of the free marriage of Lady Joan his wife, who still survives.
Heir as above, aged ½ year at Christmas in the said year.
Essex. Inq. Thursday after St. Matthias (Mathi) the Apostle, 15 Edw. I.
Pritelwell. The manor (extent given) held of Robert de Ver, earl of Oxford, service unknown, but he held nothing of the king in chief there, for Joan his wife was enfeoffed of the manor, to herself and her heirs, four years before she married the said William.
He died on the morrow of St. Thomas the Apostle in the said year.
Heir as above, aged ¾ year.
Writ to Reginald de Grey, justice of Chester, to permit John de Warenna, earl of Surrey, to hold the lands of Bromfeld and Yal and the castle of Dynasbran until one month from Easter next, and to enquire in what manner the said William held the same lands and castle, 12 Feb. 15 Edw. I.
Chester ; Flint. Inq. Tuesday before St. George, 15 Edw. I.
The jury know not whether the said William held Bromfeld and Yal and the castle of Dynasbran in his demesne as of fee or for his life or otherwise ; but Master Walter de la Mare and Robert de Tumele by command of John de Warenna, earl of Surrey, on Thursday after St. Peter ad Vincula, 12 (Edw. I), came to Wrychtesham and delivered seisin of the same lands and castle to the said William ; who took the homage of certain persons (names given) and afterwards of the whole community of the country with hands joined and raised unanimously, appointed his own bailiffs, and gave certain lands of the demesnes in the towns of Sessewyc and Hunkele to Madoc Goch and David ap Howel, and took an aid of the whole community, &c.
Similar writ to Henry de Bray, escheator, concerning the manor of Scolethorp, 12 Feb. 15 Edw. I.
Norfolk. Inq. Tuesday before St. Gregory, 15 Edw. I.
Schulthorpe. The manor (extent given) including a custom called 'bussag,' and ' andlepymen ' (?) whose toll is worth 24d. yearly, held of Sir John earl of Warrenn' for life, with reversion to the said earl his father.
He died on Sunday after St. Lucy in the said year. [i.e. 15 Dec 1286]
Heir as above, aged 38 weeks on Tuesday before St. Gregory in the said year.
C. Edw. I. File 47. (13.) 2