Greek Fire

Greek fire was an incendiary weapon developed by the Byzantine Empire in the seventh century AD, traditionally credited to a Syrian engineer named Kallinikos of Heliopolis, and became one of the Byzantine military's most closely guarded secrets, its exact composition never definitively recorded and lost to history. Deployed primarily from pressurized bronze tubes mounted on Byzantine warships, the weapon projected a burning liquid, likely petroleum-based, that famously continued burning even on water, giving Byzantine naval forces a devastating advantage in close engagements. Greek fire is credited with helping Byzantium repel two major Arab sieges of Constantinople, in 674 to 678 and again in 717 to 718, at moments when the empire's survival was genuinely in doubt, and its psychological terror value against enemy fleets may have rivaled its direct destructive power. The Byzantines maintained the secrecy of the weapon's production for centuries under direct imperial control, and though later powers developed their own incendiary formulas, none is confirmed to have precisely replicated the original Byzantine weapon, whose formula remains a genuine historical mystery.