Slavery had a very important impact on the Roman Empire. At that time, slaves were the ones that were a part of a territory that was conquered by others. As we know, the Roman Empire stretched along with a very large territory that went from Europe to Africa, so the number of slaves in the Roman Empire was large. Historians estimate that slaves summed up to 40% of the Roman population. Slaves had a very important role in the Roman economy, most of them worked on farms and plantations. Also, slaves were an important part of Roman history because when they became a part of the Roman military they led a series of rebellions.