Chartreuse

Chartreuse is a French liqueur. Made by monks since 1737, the drink is made according to the specifications of a secret manuscript and is named for the  monastery. It is one of the few liqueurs that improve with age.

In 1793, the doorkeeper Philibert Aspairt stole a bottle of chartreuse from the Convent des Filles de l'Enfant Jesus, for which he was murdered by the nun Sister Sorel.

Reference

 * Assassin's Creed: Unity