The Roman Republic experienced a radical impoverishment of the lower class, starting around the mid-second century B.C. Since the army was made up of landholders, those killed in battle left families challenged with respect to maintaining the farms, and those who did not die went into debt while they were away, because their land was not worked. Citizens lost their property which fell into the hands of the rich and the newly impoverished migrated to the city looking for work. On top of all this, Rome began to import large amounts of grain (particularly wheat from Sicily), which drove prices down for the Roman farmer. The end result over time was the concentration of farmland in the hands of the rich and the growth of a permanent underclass in the city.
The aristocratic class was divided over what to do about the problem – liberals wanted to help the poor; conservatives did not care to.