A surprisingly large number of English-speaking tourists have a problem when they arrive to Florence. They just can’t seem to find enough souvenirs that have the city’s name. You know, the usual, fridge magnets, coasters, t=shirts and other trinkets. The crux of the matter is, of course, that these tourists don’t know that the name of the city looks and sounds rather different than the familiar English version of it. Even if you are clever enough to imagine that because many English words that end in “ence” can be safely assumed to end in a “nzia” you should except to see “Florenzia” you would be wrong. Florence in Italian is Firenze. This is not uncommon for large Italian cities to have variants in the English language. Precisely because these cities have been known outside of Italy for a long time, the pronunciation of their names has been retained for centuries, reflecting how they used to be called in other parts of Europe. In the case of Florence, this has a lot to do with the fact that the pronunciation of the city’s name in Italy also changed. It used to be indeed pronounced in Latin as Florentia (“flowering”). Phonetic changes through the years had the name assume its modern form (by the way, according to the Oxford Dictionary of the English Language, there are around 2,000 words that came to English from Italy).
In this list of twenty most important Italian cities (along with the regions in which they are located), close to half of names sound and look quite different in English, compared what one would use in Italian. You might as well learn the differences in order to avoid uncomfortable situations. In general, smaller cities and villages in Italy will not display a similar problem.
Now, of course, if we are talking about the pronunciation of the once popular personal name Florence, its spelling and pronunciation woudl remain the same in Italian. By the same token, geographical names such as Florence, OR or Florence, NY they would not change if used in Italian.