Man, you're totally wrong.
Nobody ever imposed anything. Written language - letters, diaries, documents, notary deeds, legal acts, everything - has always been the same everywhere: from Swiss Ticino to Malta, from Corsica to Istria - always the same.
Written Italian evolved by itself, of course: just compare il Decamerone with Il libro del Cortegiano or Il Galateo or Goldoni or Beccaria or Manzoni.
No, trust me, the nation state Imposed a language to succeed in homogeneity, just look at the reforms they made, sending school teachers (even illiterate ones), in various places where Italian wasn’t spoken but only dialects.
As language philosopher Mikhail Bachtin said, there are two forces that control language in a geographical territory, a centripetal one and a centrifuge one.
The centripetal through institutions and schools, the state tries to impose an universal language for his state.
While the centrifuge force move away this homogenous attempt, the centrifugal force are the personal conversation, thoughts, written documents spoken in the personal language of an individua, like a dialect.
For that written language, sure official documents were written in an Italian close to the Florentine one, but that doesn’t mean everyone spoke the same language.
Normal people and illiterate ones, talked differently even in 1800.
And even if intellectuals and law men knew that kind of italian, they usually spoke and wrote official documents depending on the era; Latin, Spanish, Austrian…
Even Manzoni complained about it, in one of his letters to Chauvret, when he sees all the people in a town square in France laughing at a joke, he complains on how all the people from different places understood the joke while in Italy only some would have understood it.
Ok but now we are really going into off topic so, to save the comment I’ll talk about Natasha boobs, they Are tooo big, I hope some day we get a love route with, her natural size boobs.
Because long life to boobs, but too big boobs, is too much