Italian developed from Vulgar Latin on the Italian peninsula, standardizing specifically around the Florentine Tuscan dialect used by Dante Alighieri, Petrarch and Boccaccio in the fourteenth century, whose literary prestige established Tuscan as the model for a unified literary Italian centuries before Italy existed as a single political state, a gap between literary standard and everyday spoken dialects so wide that at Italian unification in 1861 only a small minority of the population reportedly spoke standard Italian as a native tongue, the rest speaking mutually unintelligible regional languages sometimes classified as separate Romance languages in their own right.
Italian belongs to the Romance branch of Indo-European alongside French, Spanish and Portuguese, all descended from Latin, and mass media, universal schooling and internal migration over the twentieth century gradually spread standard Italian nationwide even as regional dialects and languages, including Sicilian, Neapolitan, Venetian and Sardinian, persist as living, if now minority, spoken traditions across the peninsula and islands.
Standard Italian's Tuscan base gives it closer grammatical and lexical proximity to Latin than French or Portuguese retain, a conservatism linguists attribute partly to Tuscany's relative geographic and political continuity compared to regions that experienced heavier Germanic or other substrate influence elsewhere in Romance-speaking Europe.