It is a great pleasure to be able to introduce this revised edition of Byzantium in the seventh century. I have made a number of emendations and additions to the notes and to the bibliography, and also a brief Addendum on the current state of the question of the fate of urban centres in the seventh century. But for technical reasons I have not incorporated all the changes I would, predictably, have wished to make, simply because that would have involved the substantial expansion or rewriting of some sections to take into account the work of colleagues and scholars in the various fields upon which this book touches. This was not too difficult, however, since, six years on, I believe that the analysis of the events which so transformed the late Roman world as I have tried to present them here is still a valid interpretation of the material at our disposal. Naturally, there are areas where one would wish to add nuance, or change emphasis, but, on the whole, the broad thrust and the direction of the interpretation remain unchanged, a point reinforced, as far as I am able to judge it, by the work of other scholars in the field in the past few years. The results of a good deal of work on the literary sources – Greek, Syriac and Arabic – have now become available, for example, which adds substantially to our knowledge of both the development of older as well as newer genres.