but a slave who conducted business might be given access to an individual account or fund (peculium) that he could use as if it were his own. The terms of this account varied depending on the degree of trust and co-operation between owner and slave: a slave with an aptitude for business could be given considerable leeway to generate profit and might be allowed to bequeath the peculium he managed to other slaves of his household. Within a household or workplace, a hierarchy of slaves might exist, with one slave in effect acting as the master of other slaves. Over time slaves gained increased legal protection, including the right to file complaints against their masters. A bill of sale might contain a clause stipulating that the slave could not be employed for prostitution, as prostitutes in ancient Rome were often slaves. The burgeoning trade in eunuch slaves in the late 1st century AD prompted legislation that prohibited the castration of a slave against his will "for lust or gain." Roman slavery was not based on race. Slaves were drawn from all over Europe and the Mediterranean, including Gaul, Hispania, Germany, Britannia, the Balkans, Greece... Generally, slaves in Italy were indigenous Italians, with a minority of foreigners (including both slaves and freedmen) born outside of Italy estimated at 5% of the total in the capital at its peak, where their number was largest. Those from outside of Europe were predominantly of Greek descent, while the Jewish ones never fully assimilated into Roman society, remaining an identifiable minority. These slaves (especially the foreigners) had higher mortality rates and lower birth rates than natives, and were sometimes even subjected to mass expulsions. The average recorded age at death for the slaves of the city of Rome was extraordinarily low: seventeen and a half years (17.2 for males; 17.9 for females). During the period of republican expansionism when slavery had become pervasive, war captives were a main source of slaves. The range of ethnicities among slaves to some extent reflected that of the armies Rome defeated in war, and the conquest of Greece brought a number of highly skilled and educated slaves into Rome. Slaves were also traded in markets and sometimes sold by pirates. Infant abandonment and self-enslavement among the poor were other sources. Vernae, by contrast, were "homegrown" slaves born to female slaves within the urban household or on a country estate