The name of his [Thurston de Montfort's] wife is not known.(a) He died before 21 November, and possibly before 23 July, 1216. [Complete Peerage IX:122-3, (transcribed by Dave Utzinger)]
[a] It is possible that he married a daughter of William de Cauntelo the elder, steward of the household to King John. His son Piers wrote to Walter de Merton, Chancellor 1261-63, about the business of (Walter de Cauntelo) Lord (Bishop) of Worcester, avunculi nostri; and William de Cauntelo, brother of the bishop, was concerned with the minorities of both Thurstan and his heir. Thurstan left a younger son William, who had from his brother a life interest in property at Ringwood.