Most of the northern portion of Italy was initially inhabited by the Etruscans who can be easily referred to as the predecessors of the Romans. From the Etruscans along with other Hellenistic civilizations the Romans gained much influence in art, architecture, culture, political structure and much more.
In fact after the Romans defeated the last Etruscan King named Tarquinius Superbus the civilization of Etruria and its settlements would be one of the first additions of the Roman Republic. Eventually the Romans would occupy all of the Etruscan settlements although not much else is really known about the early period of the Roman Republic and the fall of the Etruscans.
The origins of Etruria and the Etruscans are a mystery to archaeologists presently. They were preceded by a culture known as the Villanovans. The state of Etruria was categorized as a confederation of twelve independent city-states.