In Assassin's Creed II, Florence is the Italian city where Ezio Auditore's childhood and early Assassin training begin.
The game opens in Florence in 1476, when Ezio is a young nobleman involved in family and local affairs. After the execution of his father and brothers, Ezio escapes the city with his mother and sister. He later returns and begins learning the Assassin way from his uncle Mario Auditore.
Florence was a major center of Renaissance art, finance, and politics. The game uses recognizable locations such as the Palazzo Vecchio, Santa Maria del Fiore, and the Ponte Vecchio, although its playable version simplifies and rearranges the historical city for exploration.
Venice is also a major Assassin's Creed II location, which makes it an easy alternative to choose. Ezio's travels eventually include Monteriggioni, Forlì, Venice, and Rome, but Florence is the city most closely tied to his early life and origin story.