Greek Fire was an incendiary weapon that was a closely guarded military secret. Its composition remains unknown to this day, despite multiple theories.
Greek Fire was first used by Byzantine Emperor Leon III's army, when enemy vessels laid siege to Constantinople in the year 717. In the battle, the napalm-like substance burned through the enemy fleet, forcing them to lift their attack and travel west.
In 1511, the Assassin Ezio Auditore da Firenze used Greek Fire in order to destroy several ships, which prevented him from leaving the city. The Ottoman Assassins also mounted Greek Fire weapons along the barricades they used to defend their dens from Templar attacks.
- Greek Fire was first seen in the E3 gameplay demo of Assassin's Creed: Revelations.
- In the novelization of Assassin's Creed: Brotherhood, the defenders used Greek Fire during the Siege of Viana.