The proportions of the five ratings—20-15-10-5-2½ or 2—to be discussed hereafter,[461] suggest an explanation of their origin. It would be reasonable to assume that the normal holding of the well-to-do citizen was a twenty-iugera lot and that the Servian phalanx was composed of possessors of that amount, the light-armed being their sons and others distinctly inferior in wealth. In course of a few generations as the population grew, with no corresponding territorial expansion or colonization or industrial development, and with only a limited conversion of waste to arable land, many of the lots became divided and subdivided. The result was a weakening of the phalanx at a time when the state was in the most pressing need of military resources. The institution of the five ratings as a basis for the reorganization of the army was a temporary expedient for meeting the crisis, to be superseded not long afterward by a better system founded on military pay. In all probability the introduction of the five ratings, or at least the beginning of the movement in that direction, should be closely connected with the institution of the censorship in 443 or 435.[462] The supposition would give us a sufficient reason for the creation of this new office at that time, and the strengthening of the army would explain the success of the Romans in the wars immediately following.
How the five ratings were arrayed in battle is unknown. If the front counted a thousand men (milites),[463] the classis comprised four ranks (4000), the second and third ratings one rank each, making in all six ranks of heavy troops (6000).[464] Twenty centuries could be drawn from the two ratings of light troops to complete the eight ranks when needed.[465] But the Romans undoubtedly exercised the same good judgment as the Lacedaemonians in varying their formation to suit the emergency;[466] and for that reason it is wrong to assume the same depth for all occasions or an even depth for any one occasion. The management of long lines one-man deep must have been extremely difficult, if not impossible.[467] The explanation already suggested, that the state supplied the deficiency in equipment,[468] would greatly simplify the case, for there would then exist no need of arraying the census groups in successive lines. Whatever may have been the tactic arrangement, it did not continue long, for soon after the introduction of regular pay, about 400 B.C.,[469] the distinction between the ratings ceased to have an importance for military affairs.
IV. The Question as to the Connection of the Supernumeraries and the Seniors with the Military Centuries
A number of supernumeraries termed accensi velati accompanied the army. The epithet accensi proves them to have been outside the five ratings, while velati describes them as wearing civilian dress. We are informed by the sources that they carried water and weapons to the fighting men, stepped into the places of the dead and wounded, and acted as servants to the lower officers.[470] These men could not have been organized in centuries,[471] for they were drawn up in the rear behind the light troops; they extended along the entire breadth of the army,[472] and must have greatly exceeded one hundred or even two hundred. The musicians,[473] too, who accompanied the army were not grouped in two centuries, for they were distributed throughout the army.[474] There is no reason for assuming exactly two hundred musicians[475] or exactly two hundred workmen,[476] or for supposing that any of the men of this description were organized in centuries in the army. Reasoning in a similar way in regard to the seniors, we conclude that their organization in centuries could not have belonged to the original Servian system. A military century, as the name indicates, must have contained a hundred men.[477] But in any static population there are three times as many men between seventeen and forty-six as between forty-six and sixty[478]—in Rome there were three times as many juniors as seniors; and as the number of junior and senior centuries was equal, the latter could have contained only about thirty-three each, on the supposition that the whole male population between seventeen and forty-six years was organized in centuries.
The mere fact that the senior century contained so few men suggests that it was not a military institution. This impression is confirmed by the information that the seniors were reserved for the defence of the city, while the juniors took the field in active service.[479] When we reflect that even in the early republic the seniors could not often have been called on for defence, as the juniors were ordinarily sufficient for the purpose,[480] that the manning of the walls did not necessarily require a division into companies or an equipment like that for field service, and that when it was thought expedient for the seniors to serve in centuries or cohorts, their enrolment in these companies is especially mentioned, our conviction that the senior centuries did not belong to the original Servian organization grows into a certainty.[481]
V. Conclusions as to the Servian and Early Republican Organizations; Transition to the Manipular Legion
In our search for the Servian and post-Servian schemes of military organization we found it necessary to eliminate from the discriptio centuriarum all the centuries of pedites with the exception of the juniors. But even a military century of juniors could not have remained identical with a voting century; for the former comprised a fixed number and the same for all ratings, whereas in the comitia of historical time the centuries varied greatly in size, many of them containing far more than a hundred men each. In the four lower classes each century contained as many men as the entire first class;[482] and individuals constantly shifted from one class to another as their several properties increased or diminished.[483] It is a mistake, therefore, to think of the army as identical with even the junior centuries of the comitia.[484] Doubtless when the Servian army was first introduced, its organization was made to fit actual conditions, so that all who were liable to service found their place in it; but as the political assembly of centuries was instituted many years afterward, the army with its various enlargements could have kept meanwhile no more than approximate pace with the changing population, and at no time could it include the physically disqualified, who nevertheless had a right to vote in the junior centuries of the political assembly. On the other hand there were soldiers in the army too young to be in the comitia centuriata.[485]
The conclusion as to the strength of the army in the first years of the republic, before the latter had acquired any considerable accession of territory, corresponds closely with a moderate estimate of the population under the conditions then existing. The area of the state was about 983 square kilometers (equivalent to 379.5 sq. mi. or 242,899 acres).[486] Estimating the population of this agricultural community at its maximum of sixty to the square kilometer, we should have less than 60,000 for the entire area.[487] The number of men from seventeen to sixty, the Roman military age, should be about thirty per cent of the population[488]—less therefore than 18,000. If the ratio of juniors to seniors was about three to one,[489] we should have about 13,000 juniors to 5000 seniors. But a deduction must be made for slaves and for the physically incapacitated, leaving perhaps 9000 or 10,000 juniors and 3000 or 4000 seniors. These results are not unreasonable. Making allowance for several hundred supernumeraries,[490] we should then have no more than enough juniors to fill the eighty-four centuries of foot and the six troops of horse. It is clear, therefore, that all available forces were included in the army and that the junior centuries could not have contained more than a hundred men each.
Even before the phalanx had thus been brought to perfection, modifications were being made in the equipment under the influence of the Gallic invasion.[491] The introduction of pay, about 400 B.C., as has been said,[492] broke down the distinction of equipment based on degree of wealth, and not long afterward, probably in the time of the Samnite wars, the phalanx gave way to the manipular legion, which reached its full development in the Punic wars.[493]