reached, and rigidly fixed.
The insuperable social obstacles to further technical progress – and the fundamental limits of the slave mode of production – were, in fact, strikingly illustrated by the fate of the two major inventions which were recorded under the Principate: the water-mill (Palestine at the turn of the 1st century A.D.) and the reaping machine (Gaul in the 1st century A.D.). The immense potential of the water-mill – basic to later feudal agriculture – is evident enough: for it represented the first applied use of inorganic power in economic production: as Marx commented, with its appearance, ‘the Roman Empire handed down the elementary form of all machinery in the water-wheel’.39 The Empire, however, made no general use of the invention itself. It was in practice ignored under the Principate; in the later Empire, its incidence was somewhat more frequent, but it never seems to have become a normal instrument of Ancient agriculture. Likewise, the wheeled harvester introduced to accelerate reaping in the rainy climate of the North, was never adopted on any scale outside Gaul.40 Here, the lack of interest was a reflection of a wider failure to alter the methods of Mediterranean dry-soil agriculture – with its scratch-plough and two-field system – on the heavy, moist lands of Northern Europe, which needed new instruments of labour to be fully exploited. Both cases amply demonstrate that mere technique itself is never a prime mover of economic change: inventions by individuals can remain isolated for centuries, so long as the social relations have not emerged which alone can set them to work as a collective technology. The slave mode of production had little space or time for the mill or the harvester: Roman agriculture as a whole remained innocent of them to the end. Significantly, the only major treatises of applied invention or technique to have survived from the Roman Empire were military or architectural – designed essentially for its complex of weaponry and fortifications, and its repertoire of civic ornamentation.
There was no urban salvation for the malady of the countryside, however. The Principate presided over an unprecedented range of city-building in the Mediterranean. But the quantitative expansion in the number of large and medium towns in the first two centuries of the Empire was never accompanied by any qualitative modification of the structure of overall production within it. Neither industry nor trade could ever accumulate capital or experience growth beyond the strict limits set by the economy of classical Antiquity as a whole. The regionalization of manufactures, because of transport costs, thwarted any industrial concentration and development of a more advanced division of labour in manufactures. A population overwhelmingly composed of subsistence peasants, slave-labourers and urban paupers narrowed consumer markets down to a very slender scale. Apart from the tax-farms and public contracts of the Republican epoch (whose role declined greatly in the Principate, after the Augustan fiscal reforms), no commercial companies ever developed, and funded debts did not exist: the credit system remained rudimentary. The propertied classes maintained their traditional disdain for trade. Merchants were a despised category, frequently recruited from freedmen. For manumission of administrative and domestic slaves remained a widespread practice, regularly thinning the higher ranks of the urban slave population; while the contraction of external supplies must have gradually diminished the stock of servile artisans in the cities. The economic vitality of the towns was always limited and derivative: its course reflected rather than offset that of the countryside. There were no civic springs for a reversal of the relationship between the two. Moreover, once the Principate had been consolidated, the character of the imperial State apparatus itself tended to stunt commercial enterprise. For the State was by far the largest single consumer of the Empire, and was the one real focus for mass production of necessities, which might have given birth to a dynamic manufacturing sector. The provisioning policy and peculiar structure of the imperial State precluded this, however. Throughout classical Antiquity, ordinary public works – roads, buildings, aqueducts, drains – were typically executed by slave-labour. The Roman Empire, with its massively enlarged State machine, saw a corresponding extension of this principle: for the entire armaments and a considerable proportion of the procurements supply for its military and civilian apparatus came to be furnished autarchically by its own industries, manned by sub-military personnel or hereditary state slaves.41 The one truly large-scale manufacturing sector was thus to a great extent subtracted from commodity exchange altogether. The permanent and direct use by the Roman State of slave-labour – a structural feature which lasted right down and into the Byzantine Empire – was one of the central pillars of the political economy of late Antiquity. The infrastructure of slavery found one of its most concentrated expressions within the imperial superstructure itself. Thus the State could expand, but the urban economy received little benefit from its growth: if anything, its size and weight tended to suffocate private commercial initiative and entrepreneurial activity. There was thus no increase of production in either agriculture or industry within the imperial borders to offset the silent decline in its servile manpower, once external expansion had ceased.42
The result was an incipient crisis in the whole economic and social system, by the early 3rd century, that soon developed into a pervasive breakdown of the traditional political order, amidst fierce external attacks on the Empire. The sudden dearth of sources, one of the symptoms of the crisis of the mid 3rd century, makes it very difficult retrospectively to trace its exact course or mechanisms.43 It looks as if serious strains were already surfacing in the closing years of the Antonine age. Germanic pressure on the Danubian frontiers had led to the lengthy Marcomannic wars; the silver denarius had been devalued by 25 per cent by Marcus Aurelius; the first major outbreak of social brigandage had erupted, with the menacing seizure of large regions of Gaul and Spain by the armed bands of the deserter Maternus, who even sought to invade Italy itself during the disastrous reign of Commodus.44 The accession, after a brief civil war, of the Severan house brought an African dynasty to power: regional rotation of the imperial office seemed to have functioned once again, as civic order and prosperity were apparently restored. But soon inflation became mysteriously rampant, as the currency was devalued again and again. By mid century, there was a complete collapse of the silver coinage, which reduced the denarius to 5 per cent of its traditional value, while by the end of the century, corn prices had rocketed to levels 200 times over their rates in the early Principate.45 Political stability degenerated apace with monetary stability. In the chaotic fifty years from 235 to 284, there were no less than 20 Emperors, eighteen of whom died violent deaths, one a captive abroad, the other a victim of the plague – all fates expressive of the times. Civil wars and usurpations were virtually uninterrupted, from Maximinus Thrax to Diocletian. They were compounded by a devastating sequence of foreign invasions and attacks along the frontiers, stabbing deep into the interior. Franks and other Germanic tribes repeatedly ravaged Gaul, sacking their way into Spain; Alamanni and Iuthungi marched into Italy; Carpi raided into Dacia and Moesia; Heruli overran Thrace and Greece; Goths crossed the sea to pillage Asia Minor; Sassanid Persia occupied Cilicia, Cappadocia and Syria; Palmyra detached Egypt; Mauri and Blemmyes nomads harassed North Africa. Athens, Antioch and Alexandria at different moments fell into enemy hands; Paris and Tarragona were put to the torch; Rome itself had to be refortified. Domestic political turmoil and foreign invasions soon brought successive epidemics in their train, weakening and reducing the populations of the Empire, already diminished by the destructions of war. Lands were deserted, and supply shortages in agrarian output developed.46 The tax system disintegrated with the depreciation of the currency, and fiscal dues reverted to deliveries in kind. City construction came to an abrupt halt, archaeologically attested throughout the Empire; in some regions, urban centres withered and contracted.47 In Gaul, where a breakaway imperial state was maintained with a capital at Trier for fifteen years, there were full-scale rural uprisings by the exploited masses in 283–4, the first of the Bacaudae insurrections which were to recur in the history of the Western provinces. Under intense internal and external pressure, for some fifty years – from 235 to 284 – Roman society looked as if it might collapse.
By the late 3rd and early 4th century, however, the imperial state had altered and recovered. Military security was gradually restored by a martial series of Danubian and Balkan generals who successively seized the purple: Claudius II routed the Goths in Moesia, Aurelian drove back the Alamanni from Italy and subdued Palmyra, Probus annihilated the Germanic invaders of Gaul. These successes paved the way for the reorganization of the whole structure of the Roman State in the
