FIFTEENTH-century Italy, the heart of the Renaissance, was home to Leonardo da Vinci, Machiavelli and the mighty House of Medici, patrons to Michelangelo and Botticelli.

It was also home to a young assassin named Ezio, whose arsenal includes a hidden blade, repaired by Leonardo, that he'll use to avenge the deaths of his father and brothers.

All right, that's not part of official Italian history. It's the central conceit of a new video game, Assassin's Creed II.

If you can't see the Renaissance as the setting for an action game, you don't know much about history, says creative director Patrice Desilets. He set the original 2007 Assassin's Creed in the Holy Land during the Crusades, and it sold more than eight million copies worldwide. And it helps that webs of political and religious intrigue were spun in both historical periods.

In Creed II, you play as Ezio, one in a long line of assassins, with even more weapons at his disposal than Altair, the knife-wielding protagonist of the first game.

Again, the present-day character of Desmond serves as the bridge to the past. A captive, Desmond, is forced into an MRI-like device that connects him with the memories of his ancestors. While reliving the life of Altair in Assassin's Creed, Desmond learned that those who hold him are modern-day descendants of the Knights Templar, who maintain a rivalry with the assassins.

Assassin's Creed "really needed a sequel to make sense of the idea of this machine to help you relive ancestors," Desilets says. "You understand (now that) this is the story of Desmond in the present, and he will relive a bunch of different adventures with different ancestors.”

Taking liberties with history, the game has Ezio befriending a young Leonardo, who gives the player all of his gadgets and upgrades, Desilets says. “He is a bit like James Bond's Q.”

Other historical figures factor into the story line. Ezio's father, Giovanni, also an assassin, investigates the murder of the Duke of Milan, a supporter of Florentine ruler Lorenzo de' Medici. Ezio's family gets caught in the brewing battle between the Medici and the Pazzi two years before the Pazzi attempted to murder Lorenzo in 1478.

The developers at Ubisoft's Montreal studio elaborate upon this conspiracy and place Ezio in the middle.

“This wonderfully fascinating character is involved in all these historical events,” says Marcello Simonetta, author of The Montefeltro Conspiracy, a narrative non-fiction book about the plot against Lorenzo.