69.] The Mercians, before the accession of Egbert, had very nearly attained the absolute sovereignty in the Heptarchy; they had reduced the East Angles under subjection, and established tributary princes in the kingdoms of Kent and Essex.

Northumberland was involved in anarchy; and no state of any consequence remained but that of Wessex, which, much inferior in extent to Mercia, was supported solely by the great qualities of its sovereign.

Egbert led his army against the invaders, and encountering them at Ellandun, in Wiltshire, obtained a complete victory, and by the great slaughter which he made of them in their flight, gave a mortal blow to the power of the Mercians.

Whilst he himself, in prosecution of his victory, entered their country on the side of Oxfordshire, and threatened the heart of their dominions, he sent an army into Kent, commanded by Ethelwolf, his eldest son [k], and expelling Baldred, the tributary king, soon made himself master of that country.

The kingdom of Essex was conquered with equal facility, and the East Angles, from their hatred to the Mercian government, which had been established over them by treachery and violence, and probably exercised with tyranny, immediately rose in arms, and craved the protection of Egbert [l].