Arnulf III of Boulogne was a son of Arnulf II, Count of Boulogne. He succeeded his father as Count of Boulogne from 972 to 990. On his death some genealogical reconstructions suggest his lands were divided among his three sons as follows:Baldwin received Boulogne Arnulf received Ternois likely centered on Saint-Pol-sur-Ternoise An unnamed son (unconfirmed) received Thérouanne