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
Alfred the Great Hoards dating to the Viking occupation of London in 871/2 have been excavated at Croydon, Gravesend, and Waterloo Bridge. These finds hint at the cost involved in making peace with the Vikings. For the next five years the Danes occupied other parts of England. In 876 under their new leader, Guthrum, the Danes slipped past the Saxon army and attacked and occupied Wareham in Dorset. Alfred blockaded them but was unable to take Wareham by assault. Accordingly, he negotiated a peace which involved an exchange of hostages and oaths, which the Danes swore on a "holy ring" associated with the