From
TCP1:
WILLIAM DE WARENNE, generally considered COUNT OF WARENNE in Normandy, (a dignity, which, as his parentage is uncertain, he may have acquired by creation) was b. before 1036; obtained in 1054 a grant of the Castle of Mortimer, forfeited by his relative Roger de Mortimer; was one of the Council at Lillebonne that agreed on the invasion of England in 1066, in which he took part, receiving in reward some 300 manors (of which about half were in Norfolk), together with the Castles of Lewes, co. Sussex, and Conisborough, co. York, to which be himself added that of Reigate, co. Surrey, and of Castleacre, co. Norfolk.
From March to Dec. 1067, he was, during the King's absence in Normandy, one of the Council of Regency. In 1074 he was Joint Justiciar, and, in that year, routed the rebels in Norfolk during the insurrection of the Earls of Hereford and Norfolk. He stood firm to the new King, William II (during the rebellion of Bishop Odo), and was accordingly by him
cr., about 1088, EARL OF SURREY, tho' he (as were his immediate successors) was more generally spoken of as EARL WARENNE.
He m. before 1078 and probably before 1070, Gundred, a lady whose parentage, tho' she was of "Ducal" race ("stirps ducum," as recorded on her monument), has been the cause of, probably, greater controversy than that of any other person. She d. in childbed at Castle Acre, co. Norfolk, 27 May 1085, and was bur. in the priory of Lewes, co. Sussex. He appears to have m., secondly, a da. of William and sister to Richard GOET, or GUET, of Montmirail. He d. at Lewes Castle, 24 June 1089, from the effects of a wound at the siege of Pevensey, and was bur. at Lewis priory. His widow sent 100 shillings to the monks of Ely to pray for his soul, and was apparently living in 1098.
Footnotes
[1] The Complete Peerage, GE Cokayne, 1st Edition, Volume 7 (S-T), London (1896); Surrey, pages 322-332
Bef 1036 - 1089 (> 53 years)
[1] 
