The House became rulers of a unified English nation after the descendants of Alfred the Great (871–899) down to Edward the Confessor in 1066. Edward the Elder Alfred's son united under his rule, by conquering the Viking occupied areas, Mercia and East Anglia with Wessex. Then his son, Æthelstan, extended his authority into the north, Northumbria, above the Mersey and Humber, but this was not fully consolidated until after his nephew Edgar succeeded to the throne. This period of the English monarchy is known as the Anglo-Saxon period, because the two main branches of settlers were Angles (in Mercia and East Anglia) or Saxon (in Wessex, Essex, Middlesex, Surrey, Sussex and Northumbria); a smaller group of settlers, the Jutes in Kent, Wight and in parts of east Sussex, merged with the Saxons.
Their rule was often contested, notably by the Danish king Sweyn Forkbeard who invaded in 995 and occupied the united English throne from 1013 to 1014, during the reign of Æthelred the Unready and his son Edmund Ironside. Sweyn, his son Canute and his successors ruled until 1042. After Harthacanute, there was a brief Anglo-Saxon restoration between 1042 and 1066 under Edward the Confessor a son of Æthelred, who was succeeded by Harold Godwinson, who was a member of the House of Godwin, possibly a side branch of the Cerdicings (see Ancestry of the Godwins). After the Battle of Hastings, the victorious Duke of Normandy became William I of England. Anglo-Saxon attempts to restore native rule in the person of Edgar the Ætheling, a grandson of Edmund Ironside who had originally been passed over in favour of Harold, were unsuccessful and William's descendants secured their rule. Edgar's niece Matilda of Scotland later married William's son Henry I, forming a link between the two dynasties. Henry II was a descendant of the House of Wessex in the female line, something that contemporary English commentators noted with approval.