The process of subjugation, organization and assimilation were well established during the Middle and Late Republic (265 -31 BC). Technically this meant that the defeated states first became "allies" of Rome; those who conformed to Roman cultural expectations ultimately advanced to "Latin status" ("half" citizenship, without the right to vote or stand for office at Rome) and eventually to full citizenship. The driving force in this process was the need to provide an adequate number of citizen soldiers to meet the military needs of Rome.
During the early and middle Republic this process did not constitute a "system"; each state enjoyed a unique relationship with Rome. Through trial and error the Romans eventually formalized a graduated system of rights and privileges whereby communities advanced to full participation in the Roman state. It was this system that was extended throughout the Mediterranean in the post Augustan period.
The process of conversion and integration, "Romanization", was centuries long and difficult; it was marked by wars, alliances, rebellions and cooperation. Each conflict between Rome and her neighbors led to an expansion in territory and citizen numbers. By 88 BC, and following a bloody war, all Italians south of the River Po had obtained Roman citizenship. From that point, integration proceeded rapidly so that Cicero (in 63 BC) and later Augustus (35 BC) could claim to enjoy the support of Tota Italia ("All Italy"); Rome itself became the communis patria ['common fatherland'] of Italy.
Roman experiences with the people of Italy provided a model for the Romanization of the Mediterranean world under the Casears; they also provided a model of a transnational state that would long influence European history.
Please send all inquiries to firstname.lastname@example.org