The existence of a pool of inexpensive labor in the form of enslaved people is an important factor in the economy through varying degrees throughout Roman history.
Slaves are acquired for the Roman workforce through a variety of means, including purchase from foreign merchants and the enslavement of foreign populations through military conquest.
With Rome's heavy involvement in wars of conquest in the second and first centuries BCE, tens if not hundreds of thousands of slaves at a time are imported into the Roman economy from various European and Mediterranean acquisitions.
While there is limited use for slaves as servants, craftsmen, and personal attendants, vast numbers of slaves work in mines and on the agricultural lands of Sicily and southern Italy.
For the most part, slaves are treated harshly and oppressively during the Roman republican period.
Under Republican law, a slave is not considered a person, but property.
Owners can abuse, injure or even kill their own slaves without legal consequence.
While there are many grades and types of slaves, the lowest—and most numerous—grades, who work in the fields and mines, are subject to a life of hard physical labor.
This high concentration and oppressive treatment of the slave population has led to rebellions.
In 135 BCE and 104 BCE, the First and Second Servile Wars, respectively, had erupted in Sicily, where small bands of rebels found tens of thousands of willing followers wishing to escape the oppressive life of a Roman slave.
While these were considered serious civil disturbances by the Roman Senate, taking years and direct military intervention to quell, they were never considered a serious threat to the Republic.
The Roman heartland of Italy had never seen a slave uprising, nor had slaves ever been seen as a potential threat to the city of Rome.
This all changes with the Third Servile War.
In the Roman Republic of the first century, gladiatorial games are one of the more popular forms of entertainment.
In order to supply gladiators for the contests, several training schools, or ludi, have been established throughout Italy.
In these schools, prisoners of war and condemned criminals—who are considered slaves—are taught the skills required to fight to the death in gladiatorial games.
In 73 BCE, a group of some two hundred gladiators in the Capuan school owned by Lentulus Batiatus plot an escape.
When their plot is betrayed, a force of about seventy men seizes kitchen implements, ("choppers and spits"), fight their way free from the school, and seize several wagons of gladiatorial weapons and armor.
Once free, the escaped gladiators choose leaders from their number, selecting two Gallic slaves—Crixus and Oenomaus—and Spartacus, who is said either to be a Thracian auxiliary from the Roman legions later condemned to slavery, or a captive taken by the legions.
There is some question as to Spartacus's nationality, however, as a Thraex (plural Thraces or Threses) is a type of gladiator in Rome, so the title "Thracian" may simply refer to the style of gladiatorial combat in which he had been trained.
These escaped slaves are able to defeat a small force of troops sent after them from Capua, and equip themselves with captured military equipment as well as their gladiatorial weapons.
Sources are somewhat contradictory on the order of events immediately following the escape, but they generally agree that this band of escaped gladiators plundered the region surrounding Capua, recruited many other slaves into their ranks, and eventually retired to a more defensible position on Mount Vesuvius.
