Victory over Carthage and conquests in the east transformed Rome into an Empire. By the latter part of the 2nd Century BC, the rapid expansion, massive influx of slave labor, opportunity for corruption in new provinces and the continuing development of social class disorder also brought about a distinct new era in Roman history.
While there was still considerable opposition to Roman power in the Mediterranean, the Romans suddenly found themselves as the only western super-power and the governing of this power would soon prove difficult by the Senate and the old Republican ways.
Mismanagement of the new Spanish provinces, along with revolts and resistance to Roman authority was one source of constant strife for nearly two centuries. One such event, the Numantine War against the restless Celtiberians, from 143 to 133 BC, gave the Romans access to the interior of Hispania, but also proved that continuing expansion was to be challenged at every step. Complete subjugation of Hispania wouldn't be completed until the reign of Augustus, and only after centuries of bloody fighting. The military atmosphere in Spain during the later years of the Republic would also become a hot point for rebellious leaders (ie Sertorius) who sought to take advantage of ongoing political turmoil in Rome.
The wars with Carthage had produced some 75,000 slaves and a great deal more were imported from eastern conquests (150,000 from Epirus alone). While Romans everywhere initially benefited from this new cheap labor, eventually the common masses found regular work hard to find as they had been effectively replaced by it. As Rome's economy shifted from one of labor by freedmen strictly into that of slavery, a new aristocracy arose. Slave trading was the new profit center for the elite and every excess was taken to get their share. Mistreatment and poor conditions, especially in Sicily where no other province was so inundated by slaves than the plantations there, led directly to the first of several open revolts against the institution.
The First Slave War, or Servile War, broke out in Sicily in 134 BC. According to the ancient sources, a slave owner by name of Damophilus was particularly abusive to his large slave holdings. A Syrian slave, Eunus, led a revolt which would ravage Sicily for 3 years. Declaring himself Antiochus, he captured the city of Enna, while his activities inspired another revolt under a Cilician by name of Cleon. The numbers of the slave armies grew to a combined strength of 70,000 and they took such towns as Agrigentum, Tauromenium and Catana and slave owners were slaughtered all over the island.
The revolt was eventually put down by Flacchus, who crucified no fewer than 20,000 in the end. This war would turn out to be only the beginning of slave insurrection in this time period. While it lasted 3 years, and Sicily would again be home to slave rebellions in later years, it was put down quickly with the intervention of the legions. Later rebellions, such as the one under Spartacus, would strike fear not into just the populace, but into the Roman army itself.
In the east, King Attalus III of Pergamum died in 133 BC, without heirs. Long maintaining friendship status with Rome, the entire nation of Pergamum, including Lydia, Pisidia, Lycaonia, and Pamphylia was willed to Rome upon his death. By 129 BC, he entire region would be annexed as the province of Asia Minor, and without so much as a single battle, Rome gained access to more riches of the east. Pergamum itself would become one of the most prosperous and famous cities in Asia Minor, noted for its architectural monuments, its fine library, and its schools.
This vast wealth imported from Rome's newly won provinces did more than lead to slave revolts. There was a new found political cry among the Italian tribes for equal rights as Latins. The load in military duty was equally shared among the tribes, but equal rights in voting were not. While full citizens no longer had to pay many of the states taxes, the Italians still did, and it was the patricians who benefited the most through vast acquisition of land and estates. The age old battle between patrician, equestrian and plebeian was soon to be renewed and some of Rome's most famous names would play center stage on world history.
The Gracchi brothers, Tiberius and Gaius Gracchus, would use the office of the Tribune and the citizen assemblies to upend the class structure and the inequity between rich, poor, citizen and non. The late 2nd century BC would shape the path of political machinations through to the end of the Republic. The political conniving of the Gracchi and machinations of later ambitious individuals would eventually spell the doom of the Republican system.