Before Rome created a world empire, it first conquered Italy. The main military successes of the late fourth and early third centuries BC were followed by a period in which Rome exercised power on the peninsula through a combination of direct government and treaties with allies. Colonies founded by Rome played an important part in this system, both as military outposts and as (largely) reliable allies. This thesis investigates the role of these colonies in processes of cultural change in this crucial period of Roman history. In line with recent research, it is critical of the idea that the colonies simply transferred Roman culture to new areas. Instead, it uses a broad spectrum of sources (written historical sources, inscriptions, coins, archaeological material) to map various connections that affected local developments in the colonies, and to examine how cultural models were adapted and locally accommodated in the colonies. In this way, a more dynamic image of the colonies is created: they functioned largely as independent communities in a complex cultural world, and thus actively contributed to the cultural outlook of Italy under Roman rule.