Greek fire

Greek fire was an incendiary weapon used by the Byzantine Empire from the seventh through the fourteenth century, a liquid substance that could keep burning even on water. It was first recorded around 672 CE and is credited to an architect named Kallinikos, and it played a decisive role in defending Constantinople against Arab sieges in 674 to 678 and again in 718. The Byzantines guarded its formula so closely that the exact composition was lost, though most modern scholars believe it was petroleum based, comparable to modern napalm and likely thickened with resins, with older theories involving saltpeter or quicklime now largely rejected. Byzantine forces projected it from tubes called siphones mounted on warships, threw it in grenades, and used handheld versions similar to flamethrowers in siege warfare.