King Egbert (802-839). House of Wessex. First recognized King of all of England. Queen Elizabeth II's 34th great-grandfather. During the late 8th century, when King Offa of Mercia ruled most of England, Egbert lived in exile at the court of Charlemagne. Egbert regained his kingdom in 802. Succeeded by son Aethelwulf, father of Alfred the Great.