The following is excerpted from a post to SGM, 26 Apr 1998, by Dave Utzinger:
From: UTZ (UTZ@@aol.com)
Subject: TREGOZE, part 2
Newsgroups: soc.genealogy.medieval
Date: 1998/04/26
WILLIAM DE TREGOZ, who flourished in the reign of Hen. I. and of whom the great Pipe Roll of 31 Hen. I. 1130-1, makes much mention, which document Sir William Dugdale, in his Baronage (1675), invariably refers to as of 5th Stephen, and this, because the roll was considered of that date in his early life, though Prynne, and all antiquaries of any talent, acuteness, or discrimination, had determined it of Henry the First's reign in 1668, seven years before. The said Pipe Roll of 31 Hen. I. proves William Tregoz to have been a man of much consequence, and to have been concerned in Norfolk, Essex, Berks, and Lincolnshire; and, moreover, that he then had the lands of William Peverell, of London, in farm. Tregoz married and Had issue, and very probably that Agnes Tregoz, who we find living in 9th Ric. I. as concerned in Norfolk and Essex, was his widow. His issue were, apparently, three sons and one daughter. [The Topographer and Genealogist, Volume II, 1853]
Note: Dave Utzinger's line has Robert de Tregoz, of Ewyas as son of this William. I cannot believe that a son of a man who fought at the Battle of Hastings could be father of Robert of Ewyas; therefore I am making William, indicated as father of Robert by CP, as a son of this William. The dates are at least possible with the "extra" William.