Social War
The Social War (also called the Marsi War and well as the War of the Allies) of 91-87 BCE was the result of decades of contention between Rome and its Italian allies. Roman warfare relied heavily on the Italian allies (socii), but the Roman Republic did not grant them citizenship. The main cause of the Social War was this inequality in status.
CausesThis tension had its beginnings at the very onset of the Roman expansion across the Italian peninsula. Between 500 and 275 BCE, the citizen armies of the Roman Republic brought Latium and the remainder of the peninsula under its thumb. While allowing these newly acquired allies limited self-government, Rome demanded one thing from them: loyalty. This loyalty brought with it a distinct benefit for Rome: an unlimited supply of manpower for its military campaigns. As Rome reached across the Mediterranean with its long arms into Spain, Greece, North Africa, and Asia, its demand for manpower increased. As Rome demanded more and more from its Italian allies, the tension grew with it.