He was born at Falaise, the bastard son of Robert, Duke of Normandy, by Arlette, a tanner's daughter. On his father's death in 1035, the nobles accepted him as duke, but his youth was passed in difficulty and danger. When in 1047 the lords of the western part of the duchy rebelled, Henri I of France came to his help and the rebels were defeated at Val-des-Dunes. In 1051 he visited his cousin, Edward the Confessor, and received the promise of the English succession. He married Matilda, daughter of Baudouin V, Count of Flanders, in 1053. In the next ten years William repulsed two French invasions, and in 1063 conquered Maine. Although he was never keen on actual capital punishment, William the Bastard could get touchy about jokes too near the bone and, when he captured the town of Alencon that had displayed flayed skins on its walls in allusion to the tanner's trade (his maternal grandfather, Fulbert, had been a tanner), he chopped the right hand and left foot off each citizen to teach them a lesson about laughing last. Probably in 1064, Harold was at his court and swore to help him gain the English crown on Edward's death. When, however, Edward died in 1066, Harold became king. William laid his claim and, on October 14, defeated Harold at the battle of Hastings or Senlac. Harold was slain and William was crowned on December 25. The west and north of England were subdued in 1068; but next year the north revolted, and William devastated the country between York and Durham. The constitution under William assumed a feudal aspect, the old national assembly becoming a council of the king's tenants-in-chief, and all title to land being derived from his grant. The Domesday Book contains the land settlement. He also brought the English Church into closer relations with Rome. The Conqueror's rule was stern and orderly. In 1070 there was a rebellion in the Fen Country and, under the leadership of Hereward the Wake, the rebels held out for some time in the Isle of Ely. English exiles were sheltered by the Scottish king, Malcolm, who plundered the northern shires; but William in 1072 compelled Malcolm to do him homage at Abernethy. In 1073 he reconquered Maine. He also made a successful expedition into South Wales. His eldest son, Robert, rebelled against him in Normandy in 1079. Having entered on a war with Philippe I of France in 1087, William burned Mantes. As he rode through the burning town, his horse stumbled and he received an injury of which he died at Rouen on September 9. He left Normandy to his son Robert, and England to William. 

Source: Leo van de Pas