In an attempt to explain the same tribal name being used in the Midlands and Cornwall, the historian John Morris put forward a theory in his work "The Age of Arthur" (1973) that the Cornovii from the West Midlands migrated to Cornwall about 460 AD. Morris suggested that a contingent was sent to Dumnonia to rule the land there and keep out the invading Irish, seeing that a similar situation had occurred in North Wales. Morris's theory is not generally accepted by modern scholarship: Philip Payton, in his book "Cornwall: a history" (2004), states "...the Morris thesis is not widely accepted by archaeologists and early historians, and we may safely conclude that the Cornovii located west of the Tamar were an indigenous people quite separate from their namesakes in the Midlands and Caithness."