With the fall of the Roman Empire, its territory became broken down into smaller areas all isolated from one another. The Empire and its universal strivings did indeed survive in the east, but the rise of Islam and the migration of the Slavic peoples to the Balkan peninsula severed both the sea and the overland links between Constantinople and the western parts of the empire. As Geoffrey Barraclough so aptly put it, the barbarians of Western Europe were excluded from the centres of civilization in the East (Barraclough, 1963:8).