Beside the shelf on which the work is placed there likely stands a lifelike bust of Virgil in marble in bronze. CHAPTER XVIII THE ARMY: MILITARY SERVICE: PUBLIC CAREER In the older days of Roman history the fighting forces had been a "citizen army," called out for so long as it was needed, and levied from full and true Roman citizens. In the imperial times with which we are here dealing it had become a standing army. Soldiering was a profession, for which the men volunteered, and, so far as Roman citizens were concerned, it was now seldom, if ever, the case that military service required to be made compulsory on their part. It is true that a young man of the higher classes who proposed to follow a public career, leading to higher and higher offices of state, must have gone through some amount of military training, but no other Roman was actually obliged to serve. The empire was so vast and the total of the standing forces comparatively so small that it was always possible to fill up the legions with those who had some motive or inclination that way. Theoretically the state possessed a claim upon every able-bodied man, but the population of the empire was probably a hundred millions, and to collect a total of some 320,000 soldiers, made up of Roman or romanized "citizens" and of provincial subjects in about equal shares, was a sufficiently easy task, and the recruiters could therefore afford to pick and choose. Above all we must clear our minds of the notion that the Roman soldiers necessarily came from Rome, or even from Italy. They were drawn from the empire at large, and a legion posted in Spain, for example, might be recruited from a special class of Spaniards. Roughly speaking, the regular army, extending along the frontiers from Chester to Jerusalem and from Jerusalem to Algeria, was composed of two main divisions, called respectively the "legions" and the "auxiliaries." Other special or detached forces--such as the twelve regiments of Imperial Guards and the six of the City Guard--came under neither of these headings, and we may leave them out of the question for the present.