being taken prisoner, had been forced to cede Tours and the whole of Touraine to the victor (August 1044). At the same time Geoffrey Martel had succeeded in bringing the Count of Vendôme under his suzerainty, and to this the king's consent had not been wanting.
But it was in another direction that the House of Anjou felt itself drawn. The Counts of Maine, hemmed in between Normandy and Anjou, were destined sooner or later to fall under the suzerainty of one or other of their neighbours. As early as the days of Fulk Nerra, the Counts of Anjou had succeeded in bringing them under theirs. Gervase, Bishop of Le Mans, having usurped the guardianship of the young Count Hugh III, Geoffrey Martel had marched against the prelate and put him in prison (1047 or 1048). Thus all things seemed to be moving according to Angevin interests when the king and the Duke of Normandy came upon the scene.
The intervention of the latter had been delayed by serious difficulties within his own borders. Duke Robert the Magnificent (sometimes wrongly called the Devil) had died on pilgrimage in 1035, leaving as successor an illegitimate son, William, barely eight years old. The circumstances favoured the discontented; before long rebellion had been muttering on all sides, and in 1047 it burst forth, headed by Guy, lord of Vernon and Brienne, and by the Viscounts of Coutances and Bayeux. Young William appealed to the king for help, and a battle took place at Val-es-Dunes, to the east of Caen, where Henry fought valiantly in person. It was an utter rout for the rebels, who, after a few attempts at resistance, before long submitted entirely.
The king and the duke then decided upon a joint expedition against the Count of Anjou. Together they invaded Anjou and proceeded to besiege Mouliherne which surrendered (1048). Thus, after having supported the Count of Anjou throughout his struggle with the Count of Blois, the king suddenly changed sides and became his enemy. In 1049 he renewed his attack, and while William flung himself upon Maine, the king invaded Touraine, and even momentarily succeeded in occupying the stronghold of Sainte-Maure where Geoffrey Martel advanced and besieged him.
Three years had not passed before the parts were redistributed. Geoffrey, victorious in Maine, was treating with the king (1052), and the Duke of Normandy saw his late ally take sides against him. In February 1054 the king and the count jointly invaded his duchy. But the attempt did not prosper. The invading army had been divided into two corps; Odo, the king's brother, crossing the Seine, had devastated the Caux country while Henry I and Geoffrey Martel occupied the district of Evreux. William, marching in person to meet the southern army, sent a considerable part of his troops against the northern detachment. Odo allowed himself to be surprised at Mortemer, to the east of Neufchâtel, just as his men were giving themselves up to pillage.
