the collapse of the imperial system that led to the end of imperial rule in Britain. However, Michael Jones has advanced an alternative thesis that argues that Rome did not leave Britain, but that Britain left Rome. He highlights the numerous usurpers who came from Britain in the late 4th and early 5th centuries, and points out that the supply of coinage to Britain had dried up by the early 5th century, so that administrators and troops were not getting paid. All of this, he argues, led the British people to rebel against Rome. Both of these arguments are open to criticism, and the question is still open. It was a violent period, and there was probably widespread tension, alluded to in all the written sources. This may have led to the deaths of many Britons. There are also references to plagues. Laycock (Britannia the Failed State, 2008) suggests tribal conflict, possibly even starting before 410, may have sliced up much of Britain and helped destroy the economy. The evidence from land use suggests a decline in production, which might be a sign of population decline. It is clear that some British people migrated to elsewhere in Europe, and Armorica in northwest Gaul became known as Brittany. There is also evidence of British migration to Gallaecia, in Hispania. The dates of these migrations are uncertain, but recent studies suggest that the migration from south western Britain to Brittany may have begun as early as 300 and had largely ended by 500. These settlers, unlikely to be refugees if the date was this early, made their presence felt in the naming of the westernmost, Atlantic-facing provinces of Armorica, Kerne/Cornouaille ("Kernow/Cornwall") and Domnonea ("Devon"). However, there is clear linguistic evidence for close contact between the south west of Britain and Brittany across the sub-Roman period. In Galicia, in the north west corner of the Iberian peninsula, another region of traditional Celtic culture, the Suebian Parochiale, drawn up about 580, includes a list of the principal churches of each diocese in the metropolitanate of Braga: the ecclesia Britonensis, now Bretoña (north of Lugo), which was the seat of a bishop who ministered to the spiritual needs of the British immigrants to northwestern Spain: in 572 the bishop, Mailoc, had a Celtic name. The settlers had brought their Celtic Christianity with them but finally accepted the Latin Rite at the Council of Toledo in