Among the Italic peoples, the Latins, originally situated in the Latium region, and their Latin language would come to dominate the peninsula with the Roman conquest of Italy in the 3rd century BC. The Roman Republic and later the Roman Empire dominated Italy for many centuries, and furthermore established the culture and civilization of Western Europe in general, including the adoption and subsequent spread of Christianity as state religion at the end of the 4th century.
The decline and collapse of the Western Empire by the end of the 5th century is taken to mark the end of Late Antiquity. A Lombard Kingdom of Italy was established, although parts of the peninsula remained under Byzantine rule and influence until the 11th century. The Lombard kingdom was incorporated into Francia and ultimately the Holy Roman Empire, although the rise of city-states, and especially the powerful maritime republics in the medieval period led to political fragmentation. Ultimately, after the disastrous Italian Wars, the peninsula was divided among the major foreign powers of Early Modern Europe, Spain and Austria, and later fell to the French Empire under Napoleon I, the Papal States being reduced to the control of the Holy See over Rome.