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
Battle of Tettenhall according to the "Anglo-Saxon Chronicle" defeated them and inflicted losses of many thousands including two or three kings. While little is known of the exact manoeuvres employed at the battle, it is obvious the allies trapped their Viking opponents and inflicted heavy casualties on them. The "Anglo-Saxon Chronicle" states that "many thousands of men" were killed, referring to the Danes. Seemingly unable to retreat, the Kings leading the Viking raid were both killed by the allied troops. With the Northern Danes subdued, the forces of Wessex and Mercia could be focused against those who had settled further south. It was