- "Nulla è reale, tutto è lecito."
- ―The Creed of the Italian Assassins.[src]
In 1257, the Venetian explorers Niccolò and Maffeo Polo were invited to stay at the Assassins' fortress of Masyaf by Darim Ibn-La'Ahad, the son of Altaïr Ibn-La'Ahad. After training the two to become Assassins themselves, the elderly Altaïr entrusted them with creating some Assassins Guilds and guarding his autobiographical Codex. When the Mongols eventually attacked, the Polo brothers left Masyaf towards their home in Constantinople, where they were successful in creating a guild in 1258. However, during their journey, the Polos had lost the Codex to the Mongols, thus failing in their promise to protect it. In 1259, Niccolò and Maffeo journeyed to the Mongol Empire in an effort to retrieve the Codex, but ultimately failed.
In 1269, the Polos arrived in Venice, Italy, where they created an Assassins Guild, and Niccolò trained his son Marco in the ways of the Assassins. The three of them made another journey to the Mongol Empire two years later, which resulted in Marco's successful retrieval of the Codex, which they took with them back to Italy in 1295.
Formation of the Auditore
Marco Polo passed the Codex into the hands of fellow Assassin Dante Alighieri. The next year, Dante took on the son - who would later take on the name Domenico Auditore - of a fellow Assassin as an apprentice, and the boy would later in turn take both Dante and the Codex to Spain.
In 1321, Dante was killed by the Templars, proving their continuing existence to the Assassins. The Codex was given to Domenico and he was tasked with bringing it to Spain; however, he and his family were attacked by pirates employed by the Templars while being docked in Otranto, prompting Domenico to spread the Codex' pages across several boxes in his ship to prevent the pirates from finding it. Domenico's wife was brutally abused and murdered by the pirates, but Domenico and his son survived.
Both Marco Polo and Domenico's father were killed by the Templars in 1324, and using Marco's money, Domenico temporarily settled in Florence, pretending to be part of the city's nobility by taking on the name Auditore. He later bought and renovated a villa in Monteriggioni, which he named the Villa Auditore, which became the headquarters of the Italian Assassins for nearly two centuries.
Around 1478, one of the Italian Assassins, Ezio Auditore, managed to foil a Templar scheme. The scheme involved the murder of Lorenzo de' Medici and his brother, which would allow them to take power in Florence. By preventing this, Ezio ensured that Florence remained an ally to the Assassins.
Several years later, around 1480, the same Assassin prevented the Templars from taking power in Venice, where they had murdered the Doge, Giovanni Mocenigo, to have one of their own take his place. By murdering several high-placed Templars, the Assassins managed to install a Doge that was allied to the Assassins, ensuring the allegiance of another city.
In Venice, the Italian Assassins also managed to acquire an Apple of Eden, which Ezio took the Vatican to face off against Rodrigo Borgia, Grand Master of the Templar Order, who had become Pope Alexander VI. Rodrigo and Ezio dueled, with Ezio eventually emerging victorious.
Dealing with the Borgia
The Assassin victory over Rodrigo enraged his son, Cesare Borgia. Cesare then rallied his army and attacked Monteriggioni. The attack was short but fierce, and the Templars managed to reclaim the Apple of Eden, kill Mario Auditore, and capture Caterina Sforza.
This resulted in the Italian Assassins moving to Rome, where they continued their struggle against the Borgia. The Assassins managed to break Cesare's defenses by cutting off his funds as well as the support of the French army. Upon Cesare's return to the city, he killed his father in a rage, after which he was soon imprisoned by the new Pope.
After his escape, Ezio Auditore followed him to Valencia and Viana, where he eventually managed to kill Cesare, who had become the Grand Master of the Templars after the death of his father. This broke the Templar power in Italy, allowing the Assassins there to acquire more allies, such as the new Pope.
During these more peaceful times, Ezio Auditore, now the Mentor of the Italian Assassins, left for Masyaf to search for Altaïr's library. During his absence his sister, Claudia Auditore led the Assassins. Upon Ezio's return, he decided to retire and appointed Lodovico Ariosto the new Mentor.