Answer:
Florence was the capital of Italy between 1865 and 1871, during Middle Age was a successful city, artistic, cultural and financially. This period of welfare was with the establishment of the Grand Duchy of Tuscany.
Most of its economy was based in Trades, also scientific and artistic advances made their population demure. Florence's society was really organised, people, somehow, live like in a Republic. All this variables made Florence thrive financially.