EGBERT (d. 839) was King of Wessex from 802 until 839. He claimed descent from Ingild, a brother of King Ine of Wessex. His father was a certain Ealhmund who ruled briefly in Kent c. 784 in opposition to Offa of Mercia. When King Cynewulf of Wessex died in 786, Egbert disputed with Beorhtric for possession of the kingdom. Beorhtric, Offa's protégé, came out on top and Egbert departed into exile at the Frankish court. On Beorhtric's death in 802 Egbert returned and established himself as King of Wessex in a successful revolt against Mercian ascendancy.
Egbert ruled an independent Wessex for the next twenty-three years, of which we have little record. This was succeeded by a period of frenzied activity. In 825 he defeated King Beornwulf of Mercia at the battle of Ellendun (probably Wroughton in Wiltshire) and immediately afterwards send his son Ethelwulf eastwards to wrest Kent, Surrey, Sussex and Essex from Mercian overlordship. He also received an appeal for protection from the East Anglians who had rebelled against the Mercians. The Mercian empire seemed to be falling apart as rival claimants contended for kingship over the next few years. In 829 Egbert conquered Mercia and went on to lay waste part of Northumbria and exact submission and tribute from its king Eanred. For a short period he was overlord of all the English kingdoms. But in 830 Mercia threw off West Saxon lordship and for the rest of his reign Egbert's direct authority was restricted to Wessex and the south east.
In has sometimes been claimed that Egbert was the first 'King of all England.' But this is absurd. The notion is based upon the treatment of Egbert in the Anglo-Saxon Chronicle, put together in the form in which we have it at the court of Egbert's grandson Alfred and concerned above all else to magnify the exploits of the West Saxon royal dynasty. Mercian supremacy did not end with Offa. Ninth-century Mercia may have become subject to dynastic instability---and which Anglo-Saxon kingdom had not?---but it could still produce some imposing rulers such as Cernwulf (796-821), Wiglaf [827-40] and Beorhtwulf [840-52]. Further to the north the Northumbrian King Eanred [808-40] continued to rule a kingdom stretching from the Humber to the First of Forth: the submission to Egbert in 829 had no lasting effect.
Nevertheless, Egbert's reign is an important one. In the first place, he consolidated West Saxon domination over the remaining British princes of the south-west in a series of campaigns in 815, 825, 830 and 838. Secondly, his annexation of south-eastern England in 825 was to be permanent. Kent became a dependency where West Saxon princes could learn the business of kingship; just as Egbert entrusted Kent to his son Ethelwulf, so after his accession in 839 Ethelwulf placed his son Athelstan in authority there. Egbert and Ethelwulf were at pains to cultivate good relations with the archbishops of Canterbury; they had learnt the lessons of Offa's failure in this respect. In particular, they tried to ensure that the See of Canterbury should be well-disposed not just to individual kings of Wessex but to the dynasty as a whole; in their own words in a charter of 838, 'that we and our heirs for ever afterwards may have firm and unbroken friendship from the archbishop and all his successors.' They wanted to break free from the snares of dynastic instability and discontinuity which plagued Mercia, Northumbria and their Frankish neighbours over the Channel. That they succeeded in doing so no doubt owed much to luck, but also something to shrewd management. Finally, Egbert showed that he could cope with new enemies, the Vikings. They ravaged the Island of Sheppey in 835, and defeated him at Carhampton in 836. But when in 838 they made common cause with the Britons of the south-west Egbert defeated them at Hingston Down in Cornwall. In the last battle of his life, Egbert showed that the Danes were vulnerable. [Who's Who is Roman Britain and Anglo-Saxon England, Ric