 He held Kent, though not the title of earl, until the early years of King Henry II's reign, when he returned to Flanders.William was an illegitimate son of Philip of Loo, who was the son of the Flemish count Robert the Frisian and younger brother of Robert II, Count of Flanders.William's mother was a wool carder, which further diminished his status; Louis VI of France pointed out that she never rose from that station.