“She can with much difficulty raise three thousand men, which number the single city of Megara sent heretofore to the battle of Platæa.... For of what use would the oracle be now, which was heretofore at Tegyra or at Ptous? For scarcely shall you meet, in a whole day’s time, with so much as a herdsman or shepherd in those parts.”[59]
Wallon has observed that Rome, “in the early times of the Republic, was chiefly preoccupied with having a numerous and strong population of freemen. Under the Empire she had but one anxiety—taxes.”[60]
To speak with more precision, force changed the channel through which it operated. Native farmers and native soldiers were needless when such material could be bought cheaper in the North or East. With money the cohorts could be filled with Germans; with money, slaves and serfs could be settled upon the Italian fields; and for the last century, before the great inroads began, one chief problem of the imperial administration was the regulation of the inflow of new blood from without, lacking which the social system must have collapsed.
The later campaigns on the Rhine and the Danube were really slave-hunts on a gigantic scale. Probus brought back sixteen thousand men from Germany, “the bravest and most robust of their youth,” and distributed them in knots of fifty or sixty among the legions. “Their aid was now become necessary.... The infrequency of marriage, and the ruin of agriculture, affected the principles of population; and not only destroyed the strength of the present, but intercepted the hope of future generations.”[61]
His importations of agricultural labour were much more considerable. In a single settlement in Thrace, Probus established one hundred thousand Bastarnæ; Constantius Chlorus is said to have made Gaul flourish by the herds of slaves he distributed among the landlords; in 370, large numbers of Alemanni were planted in the valley of the Po, and on the vast spaces of the public domain there were barbarian villages where the native language and customs were preserved.
Probably none of these Germans came as freemen. Many, of course, were captives sold as slaves, but perhaps the majority were serfs. Frequently a tribe, hard pressed by enemies, asked leave to pass the frontier, and settle as tributaries, that is to say as coloni. On one such occasion Constantius II. was nearly murdered. A body of Limigantes, who had made a raid, surrendered, and petitioned to be given lands at any distance, provided they might have protection. The emperor was delighted at the prospect of such a harvest of labourers, to say nothing of recruits, and went among them to receive their submission. Seeing him alone, the barbarians attacked him, and he escaped with difficulty. His troops slaughtered the Germans to the last man.
This unceasing emigration gradually changed the character of the rural population, and a similar alteration took place in the army. As early as the time of Cæsar, Italy was exhausted; his legions were mainly raised in Gaul, and as the native farmers sank into serfdom or slavery, and then at last vanished, recruits were drawn more and more from beyond the limits of the Empire. At first they were taken singly, afterwards in tribes and nations, so that, when Aëtius defeated Attila at Châlons, the battle was fought by the Visigoths under Theodoric, and the equipment of the Romans and Huns was so similar that when drawn up the lines “presented the image of civil war.”
This military metamorphosis indicated the extinction of the martial type, and it extended throughout society. Rome not only failed to breed the common soldier, she also failed to produce generals. After the first century, the change was marked. Trajan was a Spaniard, Septimius Severus an African, Aurelian an Illyrian peasant, Diocletian a Dalmatian slave, Constantius Chlorus a Dardanian noble, and the son of Constantius, by a Dacian woman, was the great Constantine.
All these men were a peculiar species of military adventurer, for they combined qualities which made them, not only effective chiefs of police, but acceptable as heads of the civil bureaucracy, which represented capital. Severus was the type, and Severus has never been better described than by Machiavelli, who said he united the ferocity of the lion to the cunning of the fox. This bureaucracy was the core of the consolidated mass called the Empire; it was the embodiment of money, the ultimate expression of force, and it recognized and advanced men who were adapted to its needs. When such men were to be found, the administration was thought good; but when no one precisely adapted for the purple appeared, and an ordinary officer had to be hired to keep the peace, friction was apt to follow, and the soldier, even though of the highest ability, was often removed. Both Stilicho and Aëtius were murdered.
The monied oligarchy which formed this bureaucracy was a growth as characteristic of the high centralization of the age, as a sacred caste is characteristic of decentralization. Perhaps the capitalistic class of the later Empire has been better understood and appreciated by Fustel de Coulanges than by any other historian.