Controlling Workers Slavery was an institution deeply rooted in the ancient world, both in the Mediterranean and in the Near East, and not even Christianity when it emerged and triumphed as the state religion (in the fourth century) seriously challenged this institution. It does not follow that the bulk of the labour in the Roman economy was performed by slaves. That may have been true of large parts of Italy in the Republican period (under Augustus there were still million slaves in a total Italian population of . million) but it was no longer true of the empire as a whole.
Slaves were an investment, and at least one Roman agricultural writer advised landowners against using them in contexts where too many might be required (for example, for harvests) or where their health could be damaged (for example, by malaria). These considerations were not based on any sympathy for the slaves but on hard economic calculation. On the other hand, if the Roman upper classes were often brutal towards their slaves, ordinary people did sometimes show much more compassion. See what one historian says about a famous incident that occurred in the reign of Nero.
As warfare became less widespread with the establishment of peace in the first century, the supply of slaves tended to decline and the users of slave labour thus had to turn either to slave breeding* or to cheaper substitutes such as wage labour which was more easily dispensable. In fact, free labour was extensively used on public works at Rome precisely because an extensive use of slave labour would have been too expensive. Unlike hired workers, slaves had to be fed and maintained throughout the year, which increased the cost of holding this kind of labour. This is probably why slaves are not widely found in the agriculture of the later period, at least not in the eastern provinces.
On the other hand, they and freedmen, that is, slaves who had been set free by their masters, were extensively used as business managers, where, obviously, they were not required in large numbers. Masters often