Mercia, kingdom of

Mercia, kingdom of Mercia dominated Anglo‐Saxon politics in the late 7th and 8th cents. The name ‘Mercians’ means ‘the borderers’ and is thought to derive from their position between the Anglo‐Saxon settlements of the east coast and British kingdoms of the west. The middle Trent valley was the heartland of the Mercian kingdom. Within this area lie the Mercian episcopal centre of Lichfield (founded 669) and the important royal centres of Repton and Tamworth.

The first Mercian king who is reliably attested is Cearl, whose daughter Cwenburh married Edwin of Deira in the early 7th cent. It is usually assumed that it was Penda (c. 626–55) who established Mercia as a major Anglo‐Saxon kingdom. He and his son Wulfhere (658–75) followed an aggressive military policy which enabled them to collect tribute from the southern Anglo‐Saxon kingdoms, Northumbria, and probably some British kingdoms as well.

The 8th cent. was dominated by two very powerful kings Æthelbald (716–57) and Offa (757–96), both of whom claimed descent from Penda's brother Eowa. They attempted to extend Mercian control to eastern parts of Wales, East Anglia, and provinces south of the Thames. Kent and Sussex became Mercian provinces. Wessex remained independent, but lost territory south of the rivers Thames and Avon to Mercia. The extended boundaries of Mercia were maintained by Cenwulf (796–821), but increasing discontent with Mercian dominance in Kent, East Anglia, and Wessex weakened Mercian hegemony. When Egbert of Wessex defeated Beornwulf of Mercia at the battle of Ellendun in 825 he was able permanently to detach Kent, Sussex, Surrey, and the East Saxons from Mercian control.

However, West Saxon successes did not really threaten the main Mercian province. It was the ‘great Danish army’ which shattered the kingdom in 874. The area became increasingly dependent on Wessex for survival and Æthelfleda of Wessex, a daughter of Alfred who had married Ceolwulf's successor Æthelred, was ruler of the province in the early 10th cent. When Æthelfleda died in 918, her brother Edward the Elder, who was already winning parts of eastern Mercia from Viking control, annexed western Mercia as well.