and 1047 Hugh IV married Bertha, daughter of Odo II, Count of Blois and widow of Alan III, Duke of Brittany. The Angevins did not want Maine to come under the influence of Blois, and Count Geoffrey Martel invaded Maine. But the Normans did not want Maine to return to the Angevin orbit, so were pulled into the conflict. The precise chronology is disputed, but it is clear that in 1051 Hugh IV died and the citizens of Le Mans opened their gate to the Angevins. Anjou wound up with effective control of most of the county, but the Normans did take several important strongholds on the Maine–Normandy border. Norman conquest and rule (1062–1070) Hugh IV's son Herbert II fled to the Norman court (though some historians say he was under Angevin control for a few years first) and his death in 1062 precipitated a succession crisis. Herbert died childless in 1062 after declaring William the Bastard, then Duke of Normandy, his heir. His sister Marguerite was engaged to William's eldest son, Robert Curthose and Herbert had taken refuge at William's court in 1056 when Geoffrey Martel, Duke of Anjou, invaded Le Mans. While the county was in Angevin hands, Anjou had its own succession problem. Duke William of Normandy claimed the county on their behalf of Herbert's young sister Margaret, betrothed to his son Robert Curthose. The other claimant was Herbert's aunt Biota, a sister of Hugh IV, and her husband Walter, Count of the Vexin. William invaded Maine in force in 1063 and despite stiff opposition from Fulk IV, Count of Anjou and from local barons such as Geoffrey of Mayenne and Hubert de Sainte-Suzanne, he controlled the county by the beginning of 1064. Biota and Walter were captured at the taking of Le Mans. They died sometime later in 1063, poisoned, it was rumoured, though there is no hard evidence for this. Norman control of Maine secured the southern border of Normandy against Anjou and is one factor which enabled William to launch his successful invasion of England in 1066. In 1069 the citizens of Le Mans revolted against the Normans. Soon some of the Manceaux barons joined the revolt, the Normans were expelled in 1070, and young Hugh V was proclaimed Count of Maine. Independent period (1070–1129) Hugh was the son of Azzo d'Este and his wife Gersendis, the other sister of Count Hugh IV. Azzo