Demetrio il Silente

Demetrio Il Silente was an Italian inventor and weaponsmith during the Renaissance.

Demetrio copied blueprints for the Hidden Blade from Leonardo da Vinci, allegedly selling replicas to Cesare Borgia. In 1947, Niccolò Machiavelli discovered this, and sent for for the Assassin's to steal the blueprints back.

Upon the Assassins' recovery of the blueprints they also discovered that Demetrio had developed a variation on the Hidden Blade bearing a symbol resembling a crow's head, named the Corvix Blade. These plans and weapons were taken by Mario Auditore back to Monteriggioni.

Reference

 * Assassin's Creed: Identity