For Edward Gibbon, the decline of the Roman Empire was a matter of blame. He did not hesitate to condemn a fatal combination of violent barbarian invasion and the growing popularity of Christianity with its pious preference for monasticism over militarism and its eagerness to welcome the end of the world. For Victorians, the fall of an imperial superstate was, above all, a matter of morality. Here was a lesson for all empire-builders: effete rulers intoxicated by the vain pomp of their glittering court ceremonies would inevitably be overwhelmed by their more vigorous and manly enemies. The Roman Empire had collapsed under the rotten weight of its own degeneracy. Many modern historians – sometimes smugly non-judgemental – have preferred to think instead in terms of the movement of peoples (rather than the invasion of barbarians) and the transformation (rather than the decline and fall) of the Roman Empire. The emergence of medieval Europe is not a matter of fault. No one needs to be held responsible.

It is to Chris Wickham's great credit that he has stepped boldly and decisively away from these old disputes. The groundwork was laid in his magisterial Framing the Early Middle Ages: Europe and the Mediterranean, 400–800 (Oxford University Press, 2005), which surveyed the complex social and economic changes that shaped