Why was the Florentine Vulgar Latin chosen as the basis for standard Italian?

Question

Standard Italian, the official language of Italy and the one Italian people speak (often along with their own local languages -or dialects-), derives from the Florentine subset of Vulgar Latin.

With the collapse of the Roman Empire, the barbaric invasions and the consequent merging with other languages (and also for other reasons), Latin developed in the so called Romance languages, which came from the vulgar (i.e., spoken by common people) versions of Latin itself.

In particular, the vulgar spoken in Florence and nearby was chosen to be standard Italian. What was the exact reason behind this historical linguistics choice? Why not other local versions of vulgar Latin?

Was it because at that time a massive stream of literary works was flourishing in the area of Tuscany? It is known that in Sicily there was this same phenomenon, namely Vulgar Sicilian had created a set of literary works, praised by Dante Alighieri himself.

So, I would like to know whether the choice was an arbitrary one or there are reasons I'm not aware of.

Answer 1

Very short answer: It just happened so.

Short answer: The poetic and narrative monuments written by Dante, Petrarca, and Boccaccio put them and their variety of Italian as a model to many later writers and critics. But it was not so automatic: there were centuries of debate, starting mostly during the Renaissance, with Pietro Bembo and many others, and with some turning points, among which the choice of Alessandro Manzoni to “risciacquare i panni in Arno” (even if his influence on Italian at large is sometimes overstated). Plus, Florentine being the “official” language of Italy has largely been a question for literate people, while less literate ones just spoke whichever variety of Italian they learned at home.

Long answer: There are whole libraries on the history of Italian and how it came to be like it is now, and especially about the so-called “Questione della lingua”.

Answer 2

As a side note: there's wide agreement about Tuscan literature having been very important in the birth of Italian literature and this is the reason why Florentine became the basis of modern Italian. But why was Tuscany so interested in literature in Italian? Because Tuscany had a very high concentration of "free cities" that represented, together with the maritime republics (one of which was also in Tuscany, Pisa), the first embryos of merchant capitalism and the new social class of the modern age, the bourgeoisie. This raised the cultural level of that area and at the same time the interest of the cultured milieu of Tuscany in the formation of a national culture and a national market.

Answer 3

I would think a major factor was the prestige of the literary works from the area of Firenze. And this prestige might have reinforced the use of Toscano as a kind of lingua franca among certain people on the peninsula way before Regno d'Italia came about. Most people however would of course only speak their local language/dialect, something that didn't really change until the advent of compulsory education.

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Edit 1

IF literary Toscano had lacked this prestige and the political unification of the peninsula had still been driven by the Regno di Sardegna, then the standard of Italian would have been Piemontese, or if the unification had been driven by the Regno delle Due Sicilie then the base would have been some form of Napolitano,

On the other hand the literary prestige of Toscano might also be seen as one of the driving forces behind the unification as such. Without this and the notion that there was such a thing as a common 'Italian' culture then the unification might not have taken place at all!

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Edit 2

That Toscano had a literary prestige did not necessarily imply that it was widely spoken at all.

Yes, there were other languages in the 13th and 14th century that was widely used like the Provençau of the troubadours and of course all the different regions and states had their own traditions, and also literary models. And for official purposes there was always Latin.

Rather Toscano was promoted as a language of culture by Pietro Bembo and other umanisti during the 16th century and spread by the use of printed books.

Why did Bembo actively promote the literary use of Toscano?

He grew up in Venice, traveled widely with his father the ambassador, including a stay in Firenze where he learned Toscano; he studied Greek in Messina, worked in Ferrara, was official historian of the Republic, and ended up as a Cardinal in Rome.

Because of his travels he had first-hand experience of different language in the north, center and south. I think his preference for Toscano as a common literary language was linguistic; Toscano belonged/belongs to the central group of languages, being neither northern nor southern. He might have thought that this would make Toscano easy to understand and acquire for writers from all over the peninsula, from Turin to Palermo.