A member of a powerful family, Walter was a younger son who was given lands around Chepstow Castle by King Henry I of England sometime before 1119.
[4] Walter's family of de Clare was a powerful one, with members of it having participated in rebellions and conspiracies against Henry's older brother King William II of England (d. 1100) in 1088 and 1095.
[5] Little is known of Walter's life, most of it deriving from the Gesta Normannorum Ducum written by William of Jumieges.
The first mention of Walter in the historical record is when he was granted the lordship of Netherwent, including Chepstow Castle beside the River Wye, by King Henry I of England.
These two charter attestations show that he was an early supporter of Stephen in the king's seizure of the throne from Henry's daughter Matilda.
Michael Altschul lists no wife in his work on the Clares,[12] and C. Warren Hollister, revising J. Horace Round's entry in the Dictionary of National Biography for the Oxford Dictionary of National Biography, states that it is unclear if Walter married.
Jennifer Ward, however, states that Walter married Isabella, a daughter of Ralph de Tosny.