Ancient Roman Slaves (c-300 - c400). Slavery in ancient Rome played an important role in society and the economy. Besides manual labor, slaves performed many domestic services, and might be employed at highly skilled jobs and professions. Accountants and physicians were often slaves. Slaves of Greek origin in particular might be highly educated. Unskilled slaves, or those sentenced to slavery as punishment, worked on farms, in mines, and at mills. Slaves were considered property under Roman law and had no legal personhood. Unlike Roman citizens, they could be subjected to corporal punishment, sexual exploitation, torture and summary execution. Over time, however, slaves gained increased legal protection, including the right to file complaints against their masters. A major source of slaves had been Roman military expansion during the Republic. The use of former soldiers as slaves led perhaps inevitably to a series of en masse armed rebellions, the Servile Wars, the last of which was led by Spartacus. During the Pax Romana of the early Roman Empire, emphasis was placed on maintaining stability, and the lack of new territorial conquests dried up this supply line of human trafficking. To maintain an enslaved work force, increased legal restrictions on freeing slaves were put into place. Escaped slaves would be hunted down and returned. There were also many cases of poor people selling their children to richer neighbors as slaves in times of hardship. Further information: Slavery in antiquity In his Institutiones, the Roman jurist Gaius wrote that the state that is recognized by the ius gentium in which someone is subject to the dominion of another person contrary to nature. The 1st century BC Greek historian Dionysius of Halicarnassus indicates that the Roman institution of slavery began with the legendary founder Romulus giving Roman fathers the right to sell their own children into slavery, and kept growing with the expansion of the Roman state. Slave ownership was most widespread throughout the Roman citizenry from the Second Punic War to the 4th century AD. The Greek geographer Strabo records how an enormous slave trade resulted from the collapse of the Seleucid Empire. The Twelve Tables, Rome's oldest legal code, has brief references to slavery, indicating that the institution was of long standing. In the tripartite division of law by the jurist Ulpian, slavery was an aspect of the ius gentium, the customary international law held in common among all peoples. The law of nations was neither considered natural law, thought to exist in nature and govern animals as well as humans, nor civil law, belonging to the emerging bodies of laws specific to a people in Western societies. All human beings are born free under natural law, but slavery was held to be a practice common to all nations, who might then have specific civil laws pertaining to slaves. In ancient warfare, the victor had the right under the ius gentium to enslave a defeated population; however, if a settlement had been reached through diplomatic negotiations or formal surrender, the people were by custom to be spared violence and enslavement. The ius gentium was not a legal code, and any force it had depended on reasoned compliance with standards of international conduct. Vernae were slaves born within a household or on a family farm or agricultural estate. There was a stronger social obligation to care for vernae, whose epitaphs sometimes identify them as such, and at times they would have been the children of free males of the household. The general Latin word for slave was servus. Throughout the Roman period many slaves for the Roman market were acquired through warfare. Many captives were either brought back as war booty or sold to traders, and ancient sources cite anywhere from hundreds to tens of thousands of such slaves captured in each war. These wars included every major war of conquest from the Monarchical period to the Imperial period, as well as the Social and Samnite Wars. The prisoners taken or re-taken after the three Roman Servile Wars also contributed to the slave supply. While warfare during the Republic provided the largest figures for captives, warfare continued to produce slaves for Rome throughout the imperial period. Piracy has a long history of adding to the slave trade, and the period of the Roman Republic was no different.