AD 410-1066 Early medieval

The history of central England from the 5th century AD, when Anglo-Saxons were invading the east coast and many Britons fled to Wales, is obscure until the reign of Penda (632-55), king of Mercia. By the early 7th century, Mercia’s territory reached from Wales to the Lincolnshire coast, and later even extended as far south as London. Under strong monarchs such as Ethelbald (716-57) and Offa (757-96) it dominated England south of the River Humber into the 9th century.

The Old English name for Mercia was Mierce, meaning the people of the borders. Its most vulnerable borders were with Wales to the west and Northumbria to the north. For much of the period central England was a theatre for warfare. The great defence of Offa’s Dyke (probably mainly constructed during Offa’s reign) kept the Welsh at bay, but there was fighting with the Northumbrians throughout the 7th century, until the Mercians defeated them at the River Trent in 679.

Mercia itself was defeated by Wessex in 825, in a dispute over the ‘debateable lands’ on its southern border, and lost its overlordship of London and the south. After the Danish invasions of 865, Mercia was divided. The northern half was occupied by the Danes and only a small area in the south remained under Anglo-Saxon rule.