In 1509, Niccolò fought in the Battle of Agnadello alongside his cousin Bartolomeo d'Alviano. As their forces were driven back, Niccolò abandoned his cousin to his fate, and Bartolomeo was eventually imprisoned by the French.
By 1510, Niccolò had settled in a manor in Lonigo, but the people of the community saw him as more of an "old soldier who had outlived his glory." In this time, Niccolò took to drinking and whoring, as well as boasting of his military exploits; earning the distaste of his townsmen.
Niccolò often made luxurious purchases in the markets, and walked the streets with courtesans on each arm, using them to feel young, while they in turn used him to feel powerful. Not even his own guards respected him, mocking their master while they were off duty.
However, Niccolò nevertheless had several allies – among them, local politicians and clergy who covered up his misdeeds – which he entertained at his manor.
In 1510, the Assassin Francesco Vecellio was sent on an assignment to sully Niccolò's reputation, as well as to eventually assassinate him. This was done in order to send a message to Niccolò's allies in Rome, who he contacted regularly through couriers.
With the ill will that many citizens already harbored for Niccolò, Francesco found it easy to incite them further, until a crowd of angry civilians finally convened in front of Niccolò's home. Using the confusion, as well as the help of several Assassin brothers, Francesco entered the manor. Francesco cornered Niccolò on the top floor, and dealt a grievous blow with his blade, however, Niccolò somehow managed to survive. Seeing that the Assassin had left, he crawled over to where he had hidden the mysterious artifact known as the Shroud.
The Piece of Eden rejuvenated him enough to escape the manor, but Niccolò realized that he would not survive the trip to another town. Thus, he wrapped himself in the Shroud to further use its powers, but instead, it tore him apart from within. As Niccolò died, his last sight was the Assassin returning to claim the Piece of Eden, as well as utter a single comment, "Disgusting."