 In 796 or 797 the Welsh engaged Mercian forces at Rhuddlan. By 798 Coenwulf was in a position to invade in return, killing Caradog ap Meirion, the King of Gwynedd. A civil war in Gwynedd in the 810s ended with the succession of Hywel ap Caradog in 816 or 817, and Coenwulf invaded again, this time ravaging Snowdonia and taking control of Rhufuniog, a small Welsh territory near Rhos. It is not clear if the Mercians were involved in a battle recorded in Anglesey in 817 or 818, but the following year Coenwulf and his army devastated Dyfed.
