In Assassin's Creed II, Florence is Ezio Auditore's family city in Renaissance Italy.
Ezio grows up in Florence during the late fifteenth century, and the city is the setting for the early part of his transformation from nobleman to Assassin. The Auditore family home, the Palazzo Auditore, is located there, and several foundational missions introduce the city's streets, political tensions, and important allies.
Assassin's Creed II later expands beyond Florence. Ezio travels to Monteriggioni, San Gimignano, Forlì, Venice, and other locations as the story develops. Venice is especially prominent, but it becomes important after Ezio has already left his birthplace and begun his vendetta.
Florence is also a historically significant Renaissance center associated with the Medici family and artists such as Leonardo da Vinci. The game uses recognizable landmarks and political figures while telling a fictionalized conspiracy story around Ezio.