The "Romans" and Italic's where inherently different groups. The Italics where another tribal group that called the peninsula home during the time of Rome, and where among the first to be conquered by them. Generally speaking, people DID NOT call themselves "Roman". That's a more modern perception derived from Post-Modernist-Nationalist ideals. Even those who where citizens of Rome, would still refer to themselves in provincial terms. Gaulic, Thracian, Germanic, Italic, Syrian, so on and so forth. Fact is that they didn't even perceive Rome as an empire in the sense that we do. Provincial powers where referred to and labeled as they would have been, Gaul, Sparta, Athens, Thrice and such. Rome was a city, the heart of the republic, the seat of power, and as such the number of people living under Rome's rule who would have actually called themselves Roman was low, if any did at all. Perhaps a person born in ROME, during the height of the Empire, to a rich family, would have said "I'm Roman!". But aside from those people. Being called Roman wasn't really a thing. You served Rome, you fought for the Glory of Rome, Rome had a Senate, and Roman Walls, and Roman ships. It's very though to explain to people. But they simply did not see the world the way we do. When the western portion of the Empire fell, Rome fell, not the populations. The populations that remained behind that came to dominate the peninsula along side the Goths, where the Italics. Thus as they adopted more changing perceptions of borders, kingdoms and sovereignty during the middle ages, and they subdued other smaller factions of the region, they exercised this domination by calling it Italy and calling themselves Italians.