Beginning with the death of Marcus Aurelius and the accession of the administratively incompetent megalomaniac Commodus, Goldsworthy seeks to explain the collapse of the Roman empire not, as it is sometimes seen, as a phenomenon created almost exclusively by external pressures but as stemming largely from a cumulative failure of leadership.

The over-reliance of insecure emperors upon the army, the tendency to reward loyalty above merit, the growth of bureaucracy as an end in itself, and the decline in revenues caused by buying off enemies with territory, all combined to hollow out the state. In consequence, its collapse, though slow in coming on account of the sheer size of the institution, was remarkably swift when it finally arrived.

This is not to deny the part played by the barbarian invasions. Indeed, Goldsworthy suggests that the reason why the eastern empire survived longer than its western counterpart was that the incursions it faced were less widespread. The Bosporus presented a significant barrier to invaders, and while the Persians posed a formidable challenge, it is arguably easier to face one large adversary that a series of smaller enemies.

The eastern empire did not lose as much territory and revenue. Thus it was able to maintain a large standing army, while in the west the army which looked good on paper was consistently under-manned. Nevertheless, the east suffered from a similar sclerosis to the west. It lingered on after the collapse of its sister, gradually diminishing in size, a venerable and impressive institution but no longer a super-power.

Goldsworthy's narrative is clear, comprehensive and, given the speed with which emperors rose and fell in the declining years, remarkably easy to follow. It offers the reader a satisfyingly coherent over-view of one of the most significant cultural earthquakes in human history.