In 1141, during the struggle between the Empress Maud and Stephen I for the throne the former conferred the Earldom of Hereford on Miles of Gloucester, so-called from his father being hereditary Constable of the shire. Only two years earlier the new Earl had supported Stephen, but it has been suggested that he went over to the Empress's in part because his overlord, the Earl of Gloucester, was one of Henry I's many bastard sons, hence Maud's half brother. (Her generous gifts to Miles of land, houses, and castles, in addition to the Earldom, may have helped win him over.) [Burke's Peerage]
------------------------------------------------
William II "Rufus" King of England granted the lordship of "Over Gwent" which included a castle at the mouth of the Genny where it joins the Usk, probably some time after 1088 to one Hamelin de Ballon, so called from his having been born at Ballon, in Maine. Subsequent holders of Over Gwent or Abergavenny included the 1st and 2nd Earls of Hereford of the 1141 creation and the 2nd Earl's four younger brothers, for all of whom a shadowy family connection with Hamelin de Ballon has been claimed, though this is very hard, if not impossible, to sustain. [Burke's Peerage (page 12) on the history of Abergavenny:]