To devote space to medieval Byzantium must evoke Gibbon's disdain. He professed reluctance to give up many pages of his History to it. The Byzantines laboured under a double despotism, the tyranny of their emperors and the ‘spiritual despotism’ which shackled thoughts as well as deeds: ‘From these considerations, I should have abandoned without regret the Greek slaves and their servile historians, had I not reflected that the fate of the Byzantine monarchy is passively connected with the most splendid and important revolutions, which have changed the state of the world.’ It is in order to illuminate the rise of Islam and the Christian west that Gibbon deigns to cover the history of Byzantium: ‘As, in his daily prayers, the Musulman of Fez or Delhi still turns his face towards the temple of Mecca, the historian's eye shall be always fixed on the city of Constantinople.’

Constantinople thus offers a convenient compass bearing to Gibbon as he charts the development of more dynamic organizations and religious movements. Byzantine historical narratives and prescriptive works are tapped as sources about other peoples. What the Greeks have to say about their own warfare, in theory or practice, serves largely to heighten the contrast between them and the vigorous barbarians. Thus ‘the love of freedom and of arms was felt, with conscious pride, by the Franks themselves, and is observed by the Greeks with some degree of amazement and terror. “The Franks”, says the emperor Constantine, “are bold and valiant to the verge of temerity; and their dauntless spirit is supported by the contempt of danger and death.”’