Battle of the Conwy In 877 they partitioned Mercia, taking the east for themselves and leaving the west to Ceolwulf. Gwynedd was also under attack from the Vikings, and in 877 King Rhodri Mawr was defeated and driven out. He returned the following year, but immediately came under attack from Mercia, which was still trying to maintain its hegemony in Wales. King Alfred's victory over the Vikings at the Battle of Edington in May 878 relieved the pressure on Mercia, and in the same year Mercia defeated and killed Rhodri Mawr. Ceolwulf died or was deposed in 879, and he was succeeded as Lord
History of England Britain was in 793 at Lindisfarne monastery as given by the "Anglo-Saxon Chronicle". However, by then the Vikings were almost certainly well-established in Orkney and Shetland, and many other non-recorded raids probably occurred before this. Records do show the first Viking attack on Iona taking place in 794. The arrival of the Vikings (in particular the Danish Great Heathen Army) upset the political and social geography of Britain and Ireland. In 867 Northumbria fell to the Danes; East Anglia fell in 869. Though Wessex managed to contain the Vikings by defeating them at Ashdown in 871, a second invading army