In Assassin's Creed II, Florence is home to Ezio Auditore's family at the beginning of the game.
Ezio grows up in Florence, where the Auditore family is involved in the city's political and commercial life. The opening chapters introduce Ezio as a young Florentine before a conspiracy leads to the execution of his father and brothers. That event begins his transformation from nobleman to Assassin and drives the revenge story that follows.
Florence is the first major setting in Assassin's Creed II and gives the game its early Renaissance identity. Players explore landmarks and districts while meeting historical figures such as Leonardo da Vinci and studying the tensions among Italian powers. Ezio later travels beyond Florence to places including Monteriggioni, Venice, Forlì, and Rome.
Venice is the most common alternative answer because it occupies a large and memorable part of the game. It is a later setting, however, not the Auditore family's home at the start. The game is primarily set in Italy during the late fifteenth century.