In 1416 , William, “styling himself William Greynville, son of Sir Theobald,” formally reaffirmed his brother John’s holdings in Bideford and Stow. [1]
“He died before 29th Henry VI [1451], for in that year John de Almescombe and Philippa his wife, late the wife of William de Graynvil, had a grant from John de Copleston and others of lands in Wildhays and Guakmore.” [2]
“By his first wife, Thomasine Cole, he left no issue, but by his second wife, Philippa, he left issue one son Thomas, who succeeded him, and two daughters, viz., Margaret, the wife of John Thorne, and Ellena, who was married to William Yeo…. According to old deeds and family records, his son Thomas was the first of the family who altogether dropped the pronoun ‘de’ which had hitherto been a prefix to the surname, although both of the last two representatives of the family had sometimes omitted it.” [3]

1 Roger Granville, The History of the Granville Family , p. 55.
2 Roger Granville, The History of the Granville Family , p. 57.
3 Roger Granville, The History of the Granville Family , p. 57.