The Kingdom of England was a sovereign state on the island of Great Britain from the 10th century, when it was unified from various Anglo-Saxon kingdoms, until 1 May 1707, when it united with Scotland to form the Kingdom of Great Britain, which would later become the United Kingdom. The Kingdom of England was among the most powerful states in Europe during the medieval and early modern periods.
Beginning in the year 886 Alfred the Great reoccupied London from the Danish Vikings and after this event he declared himself King of the Anglo-Saxons, until his death in 899. During the early tenth century, the various Anglo-Saxon kingdoms were united by Alfred's descendants Edward the Elder (reigned 899–924) and Æthelstan (reigned 924–939) to form the Kingdom of the English. In 927, Æthelstan conquered the last remaining Viking kingdom, York, making him the first Anglo-Saxon ruler of the whole of England. In 1016, the kingdom became part of the North Sea Empire of Cnut the Great, a personal union between England, Denmark and Norway. The Norman Conquest in 1066 led to the transfer of the English capital city and chief royal residence from the Anglo-Saxon one at Winchester to Westminster, and the City of London quickly established itself as England's largest and principal commercial centre.