Florence

The Florentine (Tuscan) dialect forms the basis of standard Italian.

An excerpt from the article 34 facts about Florence

It was chosen as the language that began the process of the linguistic unification of Italy. This happened thanks to the great Florentine poets: Dante Alighieri, Francesco Petrarch, and Giovanni Boccaccio, who worked for the Florentine culture and became the pillars of the Italian language.