(1028–1087). Prior to his conquest of England in 1066, William I had been duke of Normandy. Prime factors behind the success of the Conquest had been the stability he had established in Normandy and the freedom from attack that the duchy had enjoyed since the deaths of Geoffroi Martel of Anjou and the Capetian king Henry I. Such stability and safety could not have been predicted in 1035, when William, then called “the Bastard” because of his illegitimate birth, inherited the duchy at age seven from his father, Robert I the Magnificent. The young duke survived several internal challenges and through successful military campaigns and judicious alliances was able to assert his authority in the duchy and in relation to the other powers of northern France. He conquered Maine and established Norman hegemony over eastern Brittany. One of his earliest and most important triumphs outside the duchy was not a military one at all, but marriage to Matilda (d. 1083), daughter of Count Baudouin I of Flanders. The 1050/51 marriage, though initially forbidden by the papacy on grounds of consanguinity, allied William with the richest princi-pality in northern France and related him through marriage to both the German emperors and the kings of France. Matilda bore him three sons and four daughters before 1066 and seems to have been a supportive and valuable companion. She founded La Trinité, a convent for nuns, near William’s Saint-Étienne in Caen, and it is in these abbey churches that the two are buried.
William I’s conquest of England established a cross-Channel dominion that altered the balance of power in northern France. William’s rivals were quick to exploit his difficulties in ruling the far-flung, multifrontier Anglo-Norman empire, and he would spend the rest of his life fighting off a powerful alliance of French princes. Maine rebelled in 1069, and rebels there invited Foulques le Rechin of Anjou to be their count. William and King Philip 1 of France supported rival claimants in the succession crisis in Flanders in 1070–71, and an anti-Norman pact between Philip, Foulques, and Count Robert of Flanders resulted.
Security in William’s empire was further compromised by vassals who held land both on the Continent and in England. Raoul de Gael rebelled against William in 1075 and continued his struggle from his Breton lands. Philip came to relieve the besieged Raoul at Dol in 1076 and formed a Breton-Angevin-Capetian alliance. William’s rivals were also able to exploit tensions within his own family. In 1078, his eldest son, Robert Curthose, demanding independent control of Normandy and Maine, rebelled and fled Normandy. He retained considerable support within the duchy and found immediate allies in Flanders and France. Robert defeated his father at Gerberoi in 1079, but a Scottish invasion of England that same year forced a speedy reconciliation. Robert rebelled again in 1083 and again became the tool of all those who opposed William.
In 1087, William took ill on campaign in the Vexin, a region of particular contention between Normandy and France. He died outside Rouen that same year, leaving Normandy and Maine to Robert but England to his second son, William II Rufus (himself succeeded by his younger brother, Henry I). Both William II and Robert spent the rest of their lives trying to attain full possession of the empire their father had created.
