In an attempt to explain the same name being used by the Midlands and Cornwall tribes, the historian
John Morris put forward a theory in his work
The Age of Arthur (1973), that a contingent of the Cornovii from the West Midlands was sent to
Dumnonia in the mid-fifth century to rule the land there and keep out the invading Irish, seeing that a similar situation had occurred in North Wales.{{cite book Morris's theory is not generally accepted by modern scholarship.
Philip Payton, in his book
Cornwall: a history, says "...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."{{cite book ==References==