 In addition, southwestern Wales was the tribal territory of the Demetae, who had never become thoroughly Romanised.The entire region of southwestern Wales had been settled by Irish newcomers in the late 4th century, and it seems far-fetched to suggest that they were ever fully Romanised.However in the southeast Wales, following the withdrawal of the Roman legions from Britain, the town of Venta Silurum (Caerwent) remained occupied by Romano-Britons until at least the early sixth century