took place. Count Herbert II of Maine died in 1062, and William, who had betrothed his eldest son Robert to Herbert's sister Margaret, claimed the county through his son. Local nobles resisted the claim, but William invaded and by 1064 had secured control of the area. William appointed a Norman to the bishopric of Le Mans in 1065. He also allowed his son Robert Curthose to do homage to the new Count of Anjou, Geoffrey the Bearded. William's western border was thus secured, but his border with Brittany remained insecure. In 1064 William invaded Brittany in a campaign that remains obscure in its details. Its effect, though, was to destabilise Brittany, forcing the duke, Conan II, to focus on internal problems rather than on expansion. Conan's death in 1066 further secured William's borders in Normandy. William also benefited from his campaign in Brittany by securing the support of some Breton nobles who went on to support the invasion of England in 1066. In England, Earl Godwin died in 1053 and his sons were increasing in power: Harold succeeded to his father's earldom, and another son, Tostig, became Earl of Northumbria. Other sons were granted earldoms later: Gyrth as Earl of East Anglia in 1057 and Leofwine as Earl of Kent sometime between 1055 and 1057. Some sources claim that Harold took part in William's Breton campaign of 1064 and swore to uphold William's claim to the English throne at the end of the campaign, but no English source reports this trip, and it is unclear if it actually occurred. It may have been Norman propaganda designed to discredit Harold, who had emerged as the main contender to succeed King Edward. Meanwhile, another contender for the throne had emerged – Edward the Exile, son of Edmund Ironside and a grandson of Æthelred II, returned to England in 1057, and although he died shortly after his return, he brought with him his family, which included two daughters, Margaret and Christina, and a son, Edgar the Ætheling. In 1065 Northumbria revolted against Tostig, and the rebels chose Morcar, the younger brother of Edwin, Earl of Mercia, as earl in place of Tostig. Harold, perhaps to secure the support of Edwin and Morcar in his bid for the throne, supported the rebels and persuaded King Edward to replace Tostig with Morcar. Tostig went into exile in Flanders, along with his wife Judith, who was