What is the name of the Assassin's Creed II protagonist's uncle who rules Monteriggioni?

Mario Auditore is Ezio's uncle and the ruler of Monteriggioni in Assassin's Creed II.

Mario is introduced as the lord of Monteriggioni and the head of the Auditore family's country estate. He is also an experienced Assassin who explains the hidden conflict between the Brotherhood and the Templars to Ezio after the collapse of Ezio's family life in Florence.

The character is fictional, but Monteriggioni is a real walled hill town in Tuscany. The game turns its Villa Auditore into a central base that can be upgraded with money earned during the campaign. Those improvements provide both a narrative home and an economic progression system.

Mario is sometimes confused with Ezio's father, Giovanni. Giovanni is the family's Florentine patriarch and a secret Assassin at the start of the story; Mario is his brother and Ezio's uncle.