He was the first Norman king of England, also duke of Normandy, who has been called one of the first modern kings and is generally regarded as one of the outstanding figures in western European history. William was an illegitimate son and is therefore sometimes called William the Bastard. Upon the death of his father, the Norman nobles, honoring their promise to Robert, accepted William as his successor. Rebellion against the young duke broke out almost immediately, however, and his position did not become secure until 1047 when, with the aid of Henry I, king of France, he won a decisive victory over a rebel force near Caen. During a visit in 1051 to his childless cousin, Edward the Confessor, king of England, William is said to have obtained Edward's agreement that he should succeed to the English throne. In 1053, defying a papal ban, William married a descendant of King Alfred the Great, thereby strengthening his claim to the crown of England. Henry I, fearing the strong bond between Normandy and Flanders resulting from the marriage, attempted in 1054 and again in 1058 to crush the powerful duke, but on both occasions William defeated the French king's forces. Conquest of England About 1064, the powerful English noble, Harold, earl of Wessex, was shipwrecked on the Norman coast and taken prisoner by William. He secured his release by swearing to support William's claim to the English throne. When King Edward died, however, the witenagemot (royal council) elected Harold king. Determined to make good his claim, William secured the sanction of Pope Alexander II (died 1073) for a Norman invasion of England. The duke and his army landed at Pevensey on September 28, 1066. On October 14, the Normans defeated the English forces at the celebrated Battle of Hastings, in which Harold was slain. William then proceeded to London, crushing the resistance he encountered on the way. On Christmas Day he was crowned king of England in Westminster Abbey. The English did not accept foreign rule without a struggle. William met the opposition, which was particularly violent in the north and west, with strong measures; he was responsible for the devastation of great areas of the country, particularly in Yorkshire, where Danish forces had arrived to aid the Saxon rebels. By 1070 the Norman conquest of England was complete. William invaded Scotland in 1072 and forced the Scottish king Malcolm III MacDuncan (died 1093) to pay him homage. During the succeeding years the Conqueror crushed insurrections among his Norman followers, including that incited in 1075 by Ralph de Guader, 1st earl of Norfolk, and Roger Fitzwilliam, earl of Hereford, and a series of uprisings in Normandy led by his eldest son Robert, who later became Robert II, duke of Normandy. His Achievements One feature of William's reign as king was his reorganization of the English feudal and administrative systems. He dissolved the great earldoms, which had enjoyed virtual independence under his Anglo-Saxon predecessors, and distributed the lands confiscated from the English to his trusted Norman followers. He introduced the Continental system of feudalism; by the Oath of Salisbury of 1086 all landlords swore allegiance to William, thus establishing the precedent that a vassal's loyalty to the king overrode his fealty to his immediate lord. The feudal lords were compelled to acknowledge the jurisdiction of the local courts, which William retained along with many other Anglo-Saxon institutions. The ecclesiastical and secular courts were separated, and the power of the papacy in English affairs was greatly curtailed. Another outstanding accomplishment was the economic survey undertaken and incorporated in the Domesday Book in 1086. In 1087, during a campaign against King Philip I of France, William burned the town of Mantes (now Mantes-la-Jolie). William's horse fell in the vicinity of Mantes, fatally injuring him. William was succeeded by his third-born son, William II.