I have argued elsewhere that the seventh century marks a moment of cultural transformation for the East Roman or Byzantine world, not just in terms of the obvious political changes which took place, nor simply with respect to the changes in social, economic, and administrative patterns of life within the Empire or outside it, in those territories which were firmly in Muslim hands by the late 640s, but also in respect of patterns of belief and, more significantly, the ways in which people perceived their world and expressed their attitudes to what had happened. This process was not sudden, of course, nor was it simply "caused" by the Muslim conquests: much of it represented the last stages of a series of longer-term developments which reflect the evolution of late Roman 324Christian society and culture from the third century on. In the Monophysite East, change was clearly perceived by contemporaries in the sixth century. But it was the Muslim conquests which set the seal on these developments and made them irrevocable. Henceforth, Christian society in the East Mediterranean region, whether within the Empire or not, had to come to terms with the existence of a new and intellectually dynamic religious system and new political forms, within which new modes of domination and subordination were particularly significant. This is all well known, of course; the ways in which Christian culture responded to the arrival of the Arabs have been discussed, albeit usually very partially and from an understandably limited perspective (given the nature of the sources), by several scholars. 1 In particular, the emphasis that apocalyptic writings received in the second half of the seventh century has been highlighted—quite rightly—as a significant indication of a change in Christian attitudes, which were obliged to begin to reconcile the probable permanence of the new state of affairs with traditional political ideologies and millenarian assumptions. 2 I should like here to consider some of the writings attributed to one seventh-century Christian thinker and ascetic, Anastasius of Sinai. In doing so, I wish not only to relate these writings to the context in which they were compiled, both in respect of literary and theological antecedents and of specific historical events, but also to illustrate several features 325of this period of transformation common to all the cultures of the East Mediterranean zone, both in its Christian and its Muslim aspects.