Many roads lead to Byzantium, ‘the New Rome’, and guidance comes from dozens of disciplines, including art history and archaeology, theology and expertise in stone inscriptions, coins or handwriting. Indeed, those general historians who act as guides have themselves often majored in other fields, such as ancient Greece and Rome, the medieval west, the Slav or Mediterranean worlds, and even the Italian renaissance. The surest fact about the elusive ‘New Rome’ is that it lasted over a thousand years, albeit with a fifty-seven-year dislocation from 1204. Across this millennium, the questions of how, why and where the empire survived, receded and (most importantly) revived as a more or less functioning organism – and as an idea – underlie this book.

We take a narrower road than the one chosen by this volume’s predecessor, The Cambridge medieval history IV, whose first part recounted political, military and ecclesiastical history in detail from 717 until the end of the empire, and devoted several authoritative chapters to neighbouring peoples and powers; its second part contained thematic chapters, on for example law, government, the church, music, the visual arts and literature. No such comprehensive treatment of Byzantium’s culture will be attempted here. Our chapters follow the fortunes of the empire, as shifting politico-military organisation and as abiding ideal and state of mind, but do not attempt portrayal of Byzantium and its civilisation from every angle; however, some important alternative approaches to its history are sketched in the third section of this introduction (see below, pp. 53–75).