Egbert (d. 837)

Egbert, king of Wessex, a descendant of Cedric the founder; after an exile of 13 years at the court of Charlemagne ascended the throne in 800; reigned till 809, governing his people in tranquillity, when, by successful wars with the other Saxon tribes, he in two years became virtual king of all England, and received the revived title of Bretwalda; (d. 837).

Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)