Matteo Favero originally served as a captain for the House of Borgia. His enlistment was compelled by his father Sirus, who was then acting as a military instructor for the Templar Cesare Borgia. Despite Matteo's rank and his father's close ties to Cesare, his service in Cesare's army was kept a guarded secret against Cesare himself.
Around 1501, the Crows were founded under the direction of Cesare as a secret organization to hunt down the Assassins by replicating their own techniques. After the Spanish Assassin Raphael Sanchez was deceived into training the unit for more than five years in the ways of the Assassins, Matteo's father Sirus Favero took over their command, presiding over their indoctrination into Templar ideology. Sirus therefore became the Grand Master of the Crows, and as his son, Matteo took on a leading role in the organization as well, bearing the title of Master of the Crows.
In 1506, during one of their operations, the Crows and a contingent of Borgia troops set up a heavily-fortified camp around the Colosseum in Rome. Large shipments of Corvix Blades, the signature weapon of the Crows, and Crow uniforms were sent there by Sirus and received by Matteo. It was inevitable that such a conspicuous gathering of Borgia soldiers attracted the attention of the Assassins, who sent one of its agents, Lo Sparviero, to investigate.
It was while conferring with his father at the base of the Colosseum that Matteo was mistakenly identified by Lo Sparviero from the top of the Arch of Constantine as the Master Crow. As Sirus and Matteo parted ways, the latter became aware of the Assassin on his tail, but feigned ignorance. He climbed up onto one of the intermediate levels of the Colosseum, knowing all too well that the Assassin would follow closely behind. There, he led Lo Sparviero directly into a trap set by his soldiers.
While the Assassin was preoccupied with the ambush, Matteo fled higher above onto the ledge of the arena, where he awaited at a platform at the far end with a couple of guards in the event the Assassin survived. Indeed soon afterwards, Lo Sparviero came charging down the ledge towards him. A brief fight commenced, with the Assassin dispatching Matteo's guards then mortally wounding him before kicking him off the Colosseum to a sure death below.
- In Assassin's Creed: Identity, the database entry for his father, Sirus Favero, states that during his time as a Borgia captain, Matteo fought in the War of the League of Cambrai, which historically occurred from 1508 to 1516. The database presents this as though the war precedes the founding of the Crows, despite the fact that the game's events display the Crows as being active from around the time of the Siege of Monteriggioni in 1500 to Cesare Borgia's death in 1507. As Matteo himself is killed sometime after Ezio Auditore's discovery of the Temple of Pythagoras in 1506 and before Cesare's own demise, the database entry contradicts the game narrative.