22. Florence, Italy

While Florence had sent their best troops to Genoa as reinforcements, Castruccio sieged their city.

“Now, without declaring war, or in any way advising them of their peril, he suddenly made an incursion into their territory, burning and wasting their land as far as Empoli, taking several castles, and carrying off an immense booty; he then retreated back to Lucca.” (282)

Some history: Wikipedia tells me that Florence was a hub in the medieval era for trade and finance, making it one of the wealthiest cities at the time (and it continues to be one of the most expensive cities in Italy).  Many academics also consider it the birthplace of the Renaissance era.