And while the rich got richer, the poor got poorer. Lower-class Roman families — small citizen-farmers who had long been the backbone of the republic — faced a dire economic crisis. Prolonged military service had left many of their farms ruined. Unable to compete with growing estates of their senatorial neighbors, small freeholders were bought out by rich families. This began a century-long process that transformed Italy from a patchwork of small farms to a handful of huge commercial estates. The poorer Romans were reduced to being landless peasants or moving to the cities in search of wage labor. Either way, they were dislocated from their traditional ways of life and not very happy about it.

The plight of the dispossessed citizen-farmer was exacerbated by the simultaneous influx of slaves into Italy. Like all ancient societies, Rome had always used slaves. But it wasn’t until after it had emerged as the strongest power in the Mediterranean that slaves by the hundreds of thousands flooded into Italy. From physical labor to skilled arts and crafts, the work of the Roman economy was increasingly performed by slaves. So just as lower-class citizens were pushed off their land, they were forced into a labor market flush with slaves with whom they could not hope to compete.

Some in the Roman leadership could see clearly by the 130s and 120s B.C. that this socioeconomic dislocation was becoming an acute problem.