"1158. Gilbert Basset in this year received the manor of Bicester, which belonged to that 'Honour,' of the King. His son Thomas was Sheriff of Oxon, and was found upon enquiry to hold seven Knight's fees; his couins, Nicholas ten, Thurstan six and two parts of a seventh, Osmund one and a quarter, and Fulk one Knight's fee, all of the same 'Honour.' " 1
Some sources show Gilbert's wife as Edith D' OYLY [D' OILLY e.t.c.], daughter of Robert D' OYLY, Lord of Hooknorton, and Edith FitzForne DE GREYSTOKE. However, "there is doubt that she was mother of his son and heir,
Thomas Basset, progenitor of the Bassets of Headington. Keats-Rohan in DD
p.620 has Edith as wife of Wigan of Wallingford, alias Wigan nepos Brientii.
Gilbert Basset acquired d'Oilly property - Stratton, Oxon and Letcombe,
Berks. and was holding 7 knights' fees of the honour of Wallingford in 1166.
Whether he was holding this as Edith's maritagium and/or dower, or by a
grant of the king after the honour of Wallingford had escheated owing to the
lack of heirs of Alditha de Wallingford, I don't know. Thomas Basset was Philippa Basset's grandfather, and had Thomas been son of
Edith, this would have meant she was related to her husband Henry de
Newburgh in the second and third degree of consanguinity via his descent
from Robert II d'Oilly. The marriage would not have been allowed if that were the case." 2