Chibiromano is the older brother of Chibitalia, though the two didn't actually meet until after Rome disappeared. He spent over a century—from 1559 to 1713—under Spain's rule, a period that ended when Spain lost the War of Spanish Succession to the Austrian Habsburgs. Before that, he'd basically been left in the dust during the Renaissance while his younger brother got cultured by their grandfather, the Roman Empire.
When Spain finally meets him, Chibiromano turns out to be a pretty disappointing guy—lazy, insubordinate, and constantly muttering "bastard" under his breath. He's quick to blame everyone else (usually Spain) for his problems and cries easily when embarrassed or upset. Spain eventually just starts calling him a tomato because he gets so red in the face.
Underneath all the rudeness, though, he's actually insecure as hell. He knows he's more useless than his younger brother, can't do housework or art worth a damn, and figures the only reason anyone keeps him around is to cash in on Rome's legacy. Learning that Spain once made sacrifices to protect him from the Ottomans does get to him eventually—he manages to thank Spain for it, even if it kills him to admit it.
He's got a notably different approach to women compared to how he acts around men. He'll claim Spanish is too hard to learn, then turn around and use it to flirt with Belgium right in front of Spain. Like his brother, he's got that curly ahoge on his head, and he's absolutely paranoid about Spain touching it, convinced it counts as sexual harassment. In his downtime he dances the tarantella and eats pizza.
Content compiled by AnimeList.moe from publicly available sources.