In the fifth century AD the Roman empire was fatally fractured. By the 490s, the West had splintered into a series of rival kingdoms: the Vandals in North Africa, the Visigoths in Spain, the Franks in Gaul and the Ostrogoths in Italy. In England, the fragmentation of authority and the influx of Saxons from Germany provided the backdrop for the later legends of King Arthur and the Knights of the Round Table (a politically incorrect tale of a briefly unified Little Britain valiantly resisting a growing European menace). By contrast, the Roman empire in the East retained its integrity. The great arc of prosperous provinces stretching from the Balkans through Turkey, Syria, and round to Egypt and Libya continued to be controlled from Constantinople. In the core territories surrounding the imperial capital, Roman rule continued unbroken for another thousand years. It was not until 1453 that Byzantium finally fell to Arab invaders.

The great East–West divide that so sharply separates the fate of the Roman empire in the fifth century is also mirrored in the writing of its history. More attention has been focused on the West. The decline and fall of the Roman empire (in truth only half of