Excerpts from Books and Wikipedia
"The success of the Roman wars to this point had brought thousands and thousands of foreign-born captives into the Roman provinces as slaves." [Bauer: Ancient World, p. 661] "The First Servile War of 135–132 BC was a slave rebellion against the Roman Republic. Though noted to be an unsuccessful revolt, the slaves were able to thwart the Roman empire's efforts to suppress the rebellion for several years. The war was prompted by slave revolts in Enna on the island of Sicily.
Second Servile War (104-100 BC): "In Sicily, led by Athenion and Tryphon;"
"The [Spartacus] revolt began in 73 BC, with the escape of around 70 slave-gladiators from a gladiator school in Capua; they easily defeated the small Roman force sent to recapture them. Within two years, they had been joined by some 120,000 men, women and children; the able-bodied adults of this band were a surprisingly effective armed force that repeatedly showed they could withstand or defeat the Roman military . . ." [Wikipedia]