William de Fortibus Lord of Chewton

   Another name for William was William le Fort.

  General Notes:

~Ancestral Roots of Certain American Colonists Who Came to America before 1700, 8th Edition 261:32, Joan de Vivonia was the eldest daughter and coheir of William de Fortibus de Vivonia in Poitou and his wife Matilda de Ferrières. William de Fortibus a.k.a. de Fot, de Forz, de Vivonia in Poitous also styled William le Fort, lord of Chewton, Somerset, was the son of Hugh de Vivonia, sheriff of Somerset and Doreset by his wife Mabel, daughter and coheir of William Malet, a Magna Charta Surety.. ¹⁶⁰

  Information about this person:

• Background Information. ⁸⁰⁴
William de Vivonia, surnamed "de Fortibus," was the son of Hugh de Vivonia, Seneschall of Poitou, by his wife Mabel, daughter and coheir of William Mallet, Lord of Cory Mallet, Somersetshire. William de Fortibus married Maud, third daughter of William Earl Ferrièrs and coheir to her mother Sybill, daughter and coheir of William Marshall, Earl of Pembroke. William and Mabel Malet had four daughters: Joan, married to Reginald Fitz Piers; Cecilia, married to Joan de Beauchamp; Mabel, married to Fulke de russe de Awardo; and Sybill, married to Gui de Russe de Awardo.

~Burke's A Genealogical and Heraldic History of the Commoners of Great Britain and Ireland, Vol. IV, 1838 edition, p. 728

William married Matilda de Ferrières, daughter of William de Ferrières 5th Earl of Derby and Sibyl Marshall. (Matilda de Ferrières was born about 1230 in England ¹⁶⁰ and died on 12 Mar 1299 in Rochefort-en-Poitou ¹⁶⁰.)