<P> The Anglo - Saxons referred to themselves as the Engle or the Angelcynn, originally names of the Angles . They called their land Engla land, meaning "land of the English", by Æthelweard Latinized Anglia, from an original Anglia vetus, the purported homeland of the Angles (called Angulus by Bede). The name Engla land became England by haplology during the Middle English period (Engle - land, Engelond). The Latin name was Anglia or Anglorum terra, the Old French and Anglo - Norman one Angleterre . By the 14th century, England was also used in reference to the entire island of Great Britain . </P> <P> The standard title for monarchs from Æthelstan until John was Rex Anglorum ("King of the English"). Canute the Great, a Dane, was the first to call himself "King of England". In the Norman period Rex Anglorum remained standard, with occasional use of Rex Anglie ("King of England"). From John's reign onwards all other titles were eschewed in favour of Rex or Regina Anglie . In 1604 James I, who had inherited the English throne the previous year, adopted the title (now usually rendered in English rather than Latin) King of Great Britain . The English and Scottish parliaments, however, did not recognise this title until the Acts of Union of 1707 . </P> <P> The kingdom of England emerged from the gradual unification of the early medieval Anglo - Saxon kingdoms known as the Heptarchy: East Anglia, Mercia, Northumbria, Kent, Essex, Sussex, and Wessex . The Viking invasions of the 9th century upset the balance of power between the English kingdoms, and native Anglo - Saxon life in general . The English lands were unified in the 10th century in a reconquest completed by King Æthelstan in 927 CE . </P> <P> During the Heptarchy, the most powerful king among the Anglo - Saxon kingdoms might become acknowledged as Bretwalda, a high king over the other kings . The decline of Mercia allowed Wessex to become more powerful . It absorbed the kingdoms of Kent and Sussex in 825 . The kings of Wessex became increasingly dominant over the other kingdoms of England during the 9th century . In 827, Northumbria submitted to Egbert of Wessex at Dore, briefly making Egbert the first king to reign over a united England . </P>

Who was the first leader of unified england