Greek fire was an incendiary tool (weapon) used by the Eastern roman empire.

Greek fire was an incendiary weapon used by the Eastern Roman Empire beginning AD 672. Used to set enemy ships on fire, it consisted of a combustible compound emitted by a flame-throwing weapon. Some historians said it could be ignited on contact with water, and was probably based on naphtha and quicklime. The Byzantines typically used it in naval battles to great effect, as it could continue burning while floating on water. The technological advantage it provided was responsible for many key Byzantine military victories, most notably the salvation of Constantinople from the first and second Arab sieges, thus securing the empire's survival.