Leo failed to avoid the collapse of the western empire when the large naval expedition to Carthage in 468 didn’t destroy the Vandals. Military capability depended on an administrative capacity to raise taxes, on a bureaucracy which demanded and received on a recurring basis, on its organisation and record keeping along with the compliance of people with the state’s demands. The late Roman taxation system was more thorough than any that preceded, the historian says, raising the tantalising question how then did the empire decline. Since taxation was based on land and the nos on it, census registers had to be up to date but landowners usurped the rôle of officials in collecting and transferring revenues to the state, making the poor pay more and keeping most for themselves.
Breakdown or interruption was a major factor in the western empire’s decline. Barbarians controlled much of Gaul, Spain and Africa, reducing the amount of taxable land under Roman control, increasing the pressure on what they did control, making landowners offload onto tenants. The barbarians did maintain the tax systems but the Vandals themselves displaced the Roman landowning class and tax collection became lax so that when Africa was recovered in 533, the rigorous imposition of the old land tax provoked resistance.
The root cause of the fiscal crisis in the east was the growth in power of large landowners, especially in the richest province, Egypt. Justinian from 527 tried curbing the power of the great landowners of the senatorial class, staunching their corruption and increasing revenue for expenditure on war and building. The bubonic plague put paid to that: sources suggest to the historian a third of the population died 542 – 545. The plague was recurrent. Administration procedures including tax collection would’ve been brought to a standstill, he surmises. Treasury gains were reversed and declined through the sixth century. There was a diminishing ability to levy tax in Asia Minor between the late fourth and late sixth centuries. In the chaos of the early seventh century it’d’ve been harder to keep levels of taxation up. Asia Minor and the Near East were overrun by Sassanians and Egypt lost to them from 616 – 629. To pay his troops, Heraclius confiscated church silver because the capacity to tax landowners was lost. Revenue wasn’t enough to pay for even small armies in the field. Mutinies and defections occurred. State bankruptcy was a symptom of Roman decline. It was fiscal collapse caused the implosion of the eastern empire.
Roman power rested on military power, professional armies of lower ranked officers and career soldiers. Half the western regiments disappeared from the lists during the barbarian and civil warfare between 395 and 425, their numbers replenished by regrading less well equipped and trained frontier troops as a field army, as the British is by volunteers . Field army units had dropped by a quarter. Aetius’ hold on Gaul between 430 and 450 depended on his access to Hun mercenaries, probably why he didn’t protect north Italy from Attila’s depredations as I think in answer to my question why didn’t he, and that he didn’t might also explain in part the emperor’s murdering him, mistake though that was. In the east too there’s evidence at the beginning of the fifth century of demilitarisation of the native troops, of a commander pocketing the money and letting the troops go off, stealing the horses and selling them. The ethos wasn’t military, undermined by Xianity which forwarded the idea if the emperor got rid of heretics, god would get rid of the Persians, the Sassanians that is. Dependence on god saps the will to do for oneself. The emperor’s bodyguard had dropped all military pretensions during the fifth and sixth centuries. Theodosius II preferred paying Attila protection money. The Sassanians were also paid tribute. Military responsibilities were devolved on Goths and Isaurians, the latter another word for bandits. There was a growth of private armies, recruited by commanders, not unlike those of Caesar and Pompey which ended the republic. Belisarius himself and not the state paid for a militia of 7,000 in 534. A source states that in 565 troop strength was about 150,000, a quarter of the 645,000 of the fourth century. The figures aren’t reliable but there’d been a decline from the attested 65,000 of Julian in 363, invading Persia, to the 7,000 invading Italy. Heraclius couldn’t have had as much as 10,000 in his mobile counter-offensive of 627-8 in spring campaigns among barely passable mountains and without the benefit of Roman roads. The army was undermined by economic weakness, pay usually in arrears or cut. Roman force was diminished for reasons already given, including that of buying peace through diplomacy rather than with sustaining a credible threat of war, much as the EU with Russia. The Islamic conquests succeeded because of an already weakened empire.
In the west the disappearance of the villas indicates depopulation and impoverishment from the late fourth century in Britain to 550 in Africa, hardly the result of plague, more likely from insecurity at barbarian invasions though that’s disputable for Britain. From that date the small western cities also declined. The forces deployed in the Gothic wars in Italy were too small to be the cause there. More likely, the historian thinks, the plague disrupted all urban administration including street cleaning. It arrived in Marseilles in 588 and recurred till 594. Plague ravaged Thrace in 597-8 and Slavs percolated in. No public or domestic building is recorded in Aphrodisias in Asia Minor after 550. The restoration of Sagalassos after an earthquake in 500 was left incomplete by 550, the city abandoned early seventh century. He tentatively suggests the evidence is compatible with the plague’s having dealt a mortal blow, the reason the Sassanians could so easily pick off the Anatolian cities and reach the Bosporus between 609 and 623. In Syria Antioch never recovered from recession. Reduction of population concentrated wealth in fewer hands to the benefit of churches and monasteries which also profited from pious donations from grateful survivors. The plague recurred till the middle of the eighth century. Where the size of cities and villages was big enough to maintain infrastructure, they pulled through as in Egypt. Constantinople itself overcame the catastrophe. Rome too.
He takes a swipe at Xianity as contributing to the fall. Heightened religious sensibility affected the running of the state, in subservience to god’s will, undermining worldly endeavour, money going to ascetic monasteries and a priestly caste of parasites who economically contributed nothing instead of what would save the state whereas paganism hadn’t been so onerous or undermining a burden. Gibbon was right. The decline and fall was owing to Xianity, he almost agrees. Hear, hear. He has already conceded, however, religious fervour helped defeat the Sassanians but was outmatched by the simpler unifying fanatical fervour of the Islamists, much like today. He’s not above drawing parallels and might have well have mentioned Islamic State had it occurred before he was writing. This is an excellent history.