Little is known of Cahin's background save that he was a corrupt French noble who came to Cesare Borgia and the Templar Order's attention. He and Caha would perform murders in the Borgia's name dressed in colorful jester costumes. During one mission, Cahin and Caha worked with Cesare's top agent Fiora Cavazza, who was intially annoyed by the pair before warming up to them following their killing a large number of targets together. However, when Fiora Cavazza left the Templars and became an "ally" to the Assassins, she sold the two jesters out to the Assassins. Cahin managed to injure one of his assailants before finally being slain.
In 2012 his genetic memories were used to construct an Animi Avatar in his likeness dubbed "The Harlequin".
Cahin and Caha translates to "Wily Nily" in French.