Sometime between 1045 and 1047 Hugh IV married Bertha, daughter of Odo of Blois. The Angevins did not want Maine come under the influence of Blois, and count Geoffrey Martel invaded Maine. The Normans had just as little desire to see Maine return to the Angevin orbit, and they too 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.
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. While the county was in Angevin hands, Anjou had its own succession problem. Herbert's young sister Margaret was betrothed to Robert Curthose, son of duke William of Normandy, and William claimed the county on their behalf. 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, and 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 rumored, though there is no hard evidence for this.
The 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, and proclaimed young Hugh V as count of Maine. He was the son of Azzo d'Este and his wife Gersendis, the other sister of count Hugh IV. Azzo returned to Italy, leaving Gersendis in charge. The real power, however, was one of the Manceaux barons, Geoffrey of Mayenne, who may also have been Gersendis' lover.
Counts of Maine