In many ways, the composition of the Roman army reflected the range of cultural, legal, and social statuses found in the wider Roman world. Legionaries were, for the most part, recruited initially from the most culturally and legally Roman section of the population, namely Roman citizens. However, their origins changed over time, just as, for example, the origins of senators changed over time. At first (in the west, at least), most were from Italy, but through the reigns of Claudius and Nero, roughly half were provincial Roman citizens (typically from the more Roman, often colonial, populations of provinces like Gallia Narbonensis, and Baetica and Tarraconensis in Spain). By Trajan’s reign, legionaries of provincial origin outnumbered Italians by roughly four or five to one (Le Bohec 2000: 78-87; Forni 1953: 66). Subsequently, local recruitment (sometimes from veteran colonies) and recruitment of individuals born castris (‘‘in the camp,’’ soldiers’ sons living around legionary encampments) became common in most parts of the empire. For example, Wilkes’ (1999: 99) study of an inscription of legio VII Claudia (195 ce), based in Moesia Superior, shows the discharge of 142 men whose origins are preserved. At least 102 of them were recruited within the same province, six or seven born castris, 97 from the two veteran colonies in the province. A similar inscription from Alexandria (ILS 2304 = CIL III.6580 = Campbell 1994: no. 249 [194 ce]) shows 41 men whose origins are legible, 32 from Egypt, 24 of them born castris. Le Bohec’s study (1989a: 491-530) of similar evidence for men of legio III Augusta in Numidia shows about 25 percent of recruits born castris in the Antonine period and nearly 40 percent in the Severan period.
Legionary recruitment also reflected the Latin-Greek cultural distinction between the eastern and western halves of the empire, with legionaries serving in the eastern provinces mostly recruited from culturally Greek provinces and those deployed in the west mostly from culturally Latin areas in the center and west of the empire (Forni 1953: 83-5). As noted above, even status divisions within the Roman citizen body were recognized in recruitment, with individuals from the Romanized gentry of some parts of the empire drafted straight into the centurionate.