introduction

Most centuries can be said to have been, in one way or another, a watershed for Byzantium, but the case for the seventh century is particularly strong. At the beginning of the century, the Byzantine empire formed part of a political configuration that had been familiar for centuries: it was a world centred on the Mediterranean and bounded to the east by the Persian empire, in which most of the regions surrounding mare nostrum formed a single political entity – the Roman (or Byzantine) empire. It was a world whose basic economic unit was still the city and its hinterland; although it had lost much of its political significance, the city retained the social, economic and cultural high ground.

By the beginning of the seventh century, this traditional configuration was already being eroded: much of Italy was under Lombard rule, Gaul was in Frankish hands and the coastal regions of Spain, the final acquisition of Justinian’s reconquest, were soon to fall to the Visigoths. By the end of the century this traditional configuration was gone altogether, to be replaced by another which would be dominant for centuries and still marks the region today. The boundary that separated the Mediterranean world from the Persian empire was swept away: after the Arab conquest of the eastern provinces in the 630s and 640s, that boundary – the Tigris–Euphrates valley – became one of the arteries of a new empire, with its capital first in Damascus (661–750) and then in Baghdad (from 750).