The Roman legionary (Latin: legionarius, pl. legionarii) was a professional heavy infantryman of the Roman army after the Marian reforms. Legionaries had to be Roman citizens under the age of 45. They enlisted in a legion for twenty-five years of service, a change from the early practice of enlisting only for a campaign. The last five years were on veteran lighter duties.
Regular trained legionaries were known as milites and were the equivalent in rank of the modern private. Included in the ranks, aside from the milites, were the immunes, specialist soldiers with secondary roles such as engineer, artilleryman, drill and weapons instructor, carpenter and medic. These men were still fully trained legionaries, however, and would fight in the ranks if called upon. They were excused from some of the more arduous tasks such as drill and fatigues and received better pay than their comrades in arms.
On the march in unfriendly terrain, the legionary would be loaded down with armour commonly lorica hamata, lorica squamata, or 1st-3rd century lorica segmentata, shield (scutum), helmet (galea), two javelins (one heavy pilum and one light verutum), a short sword (gladius), a dagger (pugio), a pair of heavy sandals (caligae), a sarcina (marching pack), about fourteen days' worth of food, a waterskin (bladder for posca), cooking equipment, two stakes (sudes murale) for the construction of palisades, and a shovel or wicker basket.