William - came from Normandy, a near kinsman of William the Conqueror. He received large grants of land in recognition of the distinguished part he took at the battle of Hastings. He had large grants of land in several counties among which were the barony of Lewes, in Sussex, and the manors of Carletune and Benington, in Lincolnshire. So extensive indeed were those grants that his possessions resembled more the dominions of a sovereign prince than the estates of a subject. He enjoyed, too, in the highest degree, the confidence of the king, and was appointed joint Justice-General, with Richard de Benefactis, for administering justice throughout the whole realm. While in that office, some great disturbers of the public peace having refused to appear before him and his colleague, in obedience to citation, the Earl took up arms, and defeated the rebels in a battle at Fagadune, when he is said, for the purpose of striking terror, to have cut off the right foot of each of his prisoners. Of these rebels, Ralph Wahir or Gauder, Earl of Norfolk, and Roger, Earl of Hereford, were the ringleaders. He was likewise highly esteemed by King William Rufus, and was created by that monarch the first Earl of Surrey.

He came with Wm. the Conqueror, a cousin. He was awared over 300 manor houses in England. Built castle at Castle Acre, Norfolk. Coat of arms over church door in Caslte Acre. (Sources: - 1)

http://www.renderplus.com/hartgen/htm/de-warenne.htm

This earl was seated at reigate, or Holmsdale castle. Castle -Aen Castle, built soon after the conquest, and Conisborough Castle, buolt by the Saxons, belonging to King Harold.