His most famous military victory took place near Senlac Hill and preceded  victories over Edgar Atheling.
An early assassination attempt against this leader did not harm him but killed his guardians Gilbert of Brionne, Alan of Brittany and Osbern the Seneschal. Much later in life, this leader imprisoned his half-brother Odo de  Conteville and was mortally wounded in an attack at Mantes (mahnt), and his lands were divided between his sons Robert Curthose and William Rufus. His most famous military victory took place near Senlac Hill and preceded  victories over Edgar Atheling. Name this leader who believed himself to be the heir of Edward the Confessor but needed to defeat Harold Godwinson at the Battle of Hastings to become King of England.
An early assassination attempt against this leader did not harm him but killed his guardians Gilbert of Brionne, Alan of Brittany and Osbern the Seneschal.
{William I} [or {William the Conquerer;} or {William of Normandy;} accept {William II, Duke of Normandy;} do not prompt on “William II”]