Recruiting a standing force

Despite successes — and because of them — Roman commanders realized by the year

100 BC that they needed to change the empire’s military. Battling foes from Germany

to Africa to the Black Sea, the Roman Empire grew so fast that its republican legions of

citizen-soldiers couldn’t keep up. Troops posted far away on those frontiers couldn’t

come home and tend their property after a few months’ campaign.

Besides that, the prosperity that came of Rome’s expansions and the resulting boost in

trade made the wealthy patrician class in Rome even wealthier. Rich guys were

amassing big estates cultivated by slaves instead of by citizen-farmer-soldiers, the

small landholders who traditionally manned the legions. And slaves were exempt from

military service.

Rome struggled to fill the legions’ ranks. Recruiters began conveniently overlooking the

property ownership requirement for service. Commanders turned to the urban poor to

fill out their rosters, but things just weren’t the same. These new guys didn’t have the

same stake in the empire. They were harder to discipline.

Gaius Marius, a lowborn soldier who rose to the political office of consul, figured the

time had arrived for Rome to ditch the old civil militia idea and officially make the

army a full-time, professional gig.

The professional army worked. The military became an attractive career choice and a

means of upward mobility. There was a downside, however. Instead of the citizen-

soldiers’ loyalty to Rome, the new pros were loyal to their commanders first. The

republic became vulnerable to civil wars. A military leader whose troops were more

loyal to him than to the government may have fancied himself a dictator or emperor.