WILLIAM, son of Walter, witnessed deeds of the Gant family in the middle of the 12th century. In 1166 he was tenant of Simon, Earl of Northampton, for 6 1/5 knights' fees; and he made gifts to the abbey of Louth Park and to the priories of Sempringham and Greenfield, Lincs. He married (----), sister of Gilbert (DE GANT), EARL OF LINCOLN, daughter of Walter DE GANT, by Maud, daughter of Stephen, COUNT OF BRITTANY. He died before 1198. [Complete Peerage XII/2:436-7, (transcribed by Dave Utzinger)]
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William FITZWALTER, of Wells and Claxby, Norfolk, by . . ., sister of Gilbert (DE GANT), EARL OF LINCOLN, and daughter of Walter DE GANT. [Complete Peerage]
Note: I don't find a Claxby, Norfolk; there is a Claxby in Lincolnshire, whose registration district town is Spilsby--the same as Well, which it must be near.