The New Military Organization
He held in his hand a formidable weapon in the newly organized army. Previously to his time the fundamental principle of the Servian constitution--by which the levy was limited entirely to the burgesses possessed of property, and the distinctions as to armour were regulated solely by the property qualification(2)--had necessarily been in various respects relaxed. The minimum census of 11,000 -asses- (43 pounds), which bound its possessor to enter the burgess-army, had been lowered to 4000 (17 pounds;(3)). The older six property-classes, distinguished by their respective kinds of armour, had been restricted to three; for, while in accordance with the Servian organization they selected the cavalry from the wealthiest, and the light-armed from the poorest, of those liable to serve, they arranged the middle class, the proper infantry of the line, no longer according to property but according to age of service, in the three divisions of -hastati-, -principes-, and -triarii-. They had, moreover, long ago brought in the Italian allies to share to a very great extent in war-service; but in their case too, just as among the Roman burgesses, military duty was chiefly imposed on the propertied classes. Nevertheless the Roman military system down to the time of Marius rested in the main on that primitive organization of the burgess-militia. But it was no longer suited for the altered circumstances. The better classes of society kept aloof more and more from service in the army, and the Roman and Italic middle class in general was disappearing; while on the other hand the considerable military resources of the extra-Italian allies and subjects had become available, and the Italian proletariate also, properly applied, afforded at least a very useful material for military objects. The burgess- cavalry,(4) which was meant to be formed from the class of the wealthy, had practically ceased from service in the field even before the time of Marius. It is last mentioned as an actual corps d'armee in the Spanish campaign of 614, when it drove the general to despair by its insolent arrogance and its insubordination, and a war broke out between the troopers and the general, waged on both sides with equal unscrupulousness. In the Jugurthine war it continues to appear merely as a sort of guard of honour for the general and foreign princes; thenceforth it wholly disappears. In like manner the filling up of the complement of the legions with properly qualified persons bound to serve proved in the ordinary course of things difficult; so that exertions, such as were necessary after the battle of Arausio, would have been in all probability really impracticable with the retention of the existing rules as to the obligation of service. On the other hand even before the time of Marius, especially in the cavalry and the light infantry, extra-Italian subjects--the heavy mounted troopers of Thrace, the light African cavalry, the excellent light infantry of the nimble Ligurians, the slingers from the Baleares--were employed in ever-increasing numbers even beyond their own provinces for the Roman armies; and at the same time, while there was a want of qualified burgess-recruits, the non- qualified poorer burgesses pressed forward unbidden to enter the army; in fact, from the mass of the civic rabble without work or averse to it, and from the considerable advantages which the Roman war-service yielded, the enlistment of volunteers could not be difficult. It was therefore simply a necessary consequence of the political and social changes in the state, that its military arrangements should exhibit a transition from the system of the burgess-levy to the system of contingents and enlisting; that the cavalry and light troops should be essentially formed out of the contingents of the subjects--in the Cimbrian campaign, for instance, contingents were summoned from as far as Bithynia; and that in the case of the infantry of the line, while the former arrangement of obligation to service was not abolished, every free-born burgess should at the same time be permitted voluntarily to enter the army as was first done by Marius in 647.
To this was added the reducing the infantry of the line to a level, which is likewise to be referred to Marius. The Roman method of aristocratic classification had hitherto prevailed also within the legion. Each of the four divisions of the -velites-, the -hastati-, the -principes-, and the -triarii---or, as we may say, the vanguard, the first, second, and third line--had hitherto possessed its special qualification for service, as respected property or age, and in great part also its distinctive equipment; each had its definite place once for all assigned in the order of battle; each had its definite military rank and its own standard. All these distinctions were now superseded. Any one admitted as a legionary at all needed no further qualification in order to serve in any division; the discretion of the officers alone decided as to his place. All distinctions of armour were set aside, and consequently all recruits were uniformly trained. Connected, doubtless, with this change were the various improvements which Marius introduced in the armament, the carrying of the baggage, and similar matters, and which furnish an honourable evidence of his insight into the practical details of the business of war and of his care for his soldiers; and more especially the new method of drill devised by Publius Rutilius Rufus (consul 649) the comrade of Marius in the African war. It is a significant fact, that this method considerably increased the military culture of the individual soldier, and was essentially based upon the training of the future gladiators which was usual in the fighting- schools of the time. The arrangement of the legion became totally different. The thirty companies (-manipuli-) of heavy infantry, which-- each in two sections (-centuriae-) composed respectively of 60 men in the first two, and of 30 men in the third, division--had hitherto formed the tactical unit, were replaced by 10 cohorts (-cohortes-) each with its own standard and each of 6, or often only of 5, sections of 100 men apiece; so that, although at the same time 1200 men were saved by the suppression of the light infantry of the legion, yet the total numbers of the legion were raised from 4200 to from 5000 to 6000 men. The custom of fighting in three divisions was retained, but, while previously each division had formed a distinct corps, it was in future left to the general to distribute the cohorts, of which he had the disposal, in the three lines as he thought best.