The last in the series is an ever-more dizzying whirligig of passing characters and incidents, few of them with enough purchase for this to be more than a shallow parade. Maybe that is the nature of the subject matter, given the sources – but who were these people?

Among the positives, what does stand out is that the Roman Empire, for some time before the end came, was at last truncated to a few scraps of land around Constantine’s city and in the south of Greece, and to almost complete powerlessness; that the population of the great city was reduced to a few tens of thousands, with much of the land within its walls given over to agriculture; and that in its final decades its emperors were obliged to go on tours of Europe begging for military and financial support (rarely forthcoming), one even going as far as England, where he spent a month with Henry IV at Eltham in what is now the Borough of Greenwich.

But when the end came, it came heroically; and the knowledge disseminated by the refugees, having been kept in-house for a thousand years since the end of the classical age, now kick-started the modern world. Byzantium seems so far away, yet it is the chief conduit through which we know about what went before as well as having been an astonishing civilization in its own right (if also barbarous in its ruthlessness). This version of it, while often seeming superficial, at least sets the record straight on how important it was, while much of the time spinning a good yarn.