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 Ashdown the surrounding countryside. Alfred reputedly took his favourite white mare and rode up onto Blowingstone Hill (near Kingston Lisle), where stood an ancient perforated sarsen stone, called the "Blowing Stone". Anyone with the appropriate skill could generate a booming sound from this stone, by blowing into one of its holes. Alfred took a deep breath and was able to sound the alarm across the downs. All over the surrounding country, men were woken and gathered to defend their homes. In late 870, King Ethelred led the army of Wessex against the Danes in their stronghold at Reading. The attack failed,