Greek fire

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. The impression made by Greek fire on the western European Crusaders was such that the name was applied to any sort of incendiary weapon, including those used by Arabs, the Chinese, and the Mongols. However, these mixtures used formulas different from that of Byzantine Greek fire, which was a closely guarded state secret. Byzantines also used pressurized nozzles to project the liquid onto the enemy, in a manner resembling a modern flamethrower. The composition of Greek fire remains a matter of speculation and debate, with various proposals including combinations of pine resin, naphtha, quicklime, calcium phosphide, sulfur, or niter. Usage of the term "Greek fire" has been general in English and most other languages since the Crusades, but original Byzantine sources called the substance a variety of names, such as "sea fire" (Medieval Greek: πῦρ θαλάσσιον ), "Roman fire" (πῦρ ῥωμαϊκόν ), "war fire" (πολεμικὸν πῦρ ), "liquid fire" (ὑγρὸν πῦρ ), "sticky fire" (πῦρ κολλητικόν ), or "manufactured fire" (πῦρ σκευαστόν ). Incendiary and flaming weapons were used in warfare for centuries before Greek fire was invented. They included a number of sulfur-, petroleum-, and bitumen-based mixtures. Incendiary arrows and pots containing combustible substances surrounded by caltrops or spikes, or launched by catapults, were used as early as the 9th century BC by the Assyrians and were extensively used in the Greco-Roman world as well.