Liquid fire (Greek fire to the barbarians) was an incendiary weapon used by the Byzantine Empire. The Byzantines typically used it in naval battles to great effect as it could continue burning even on water. It provided a technological advantage, and was responsible for many key Byzantine military victories, most notably the salvation of Constantinople from two Arab sieges, thus securing the Empire's survival. The Byzantine formula was a closely guarded state secret, whose composition has now been lost. As a result, its ingredients are a much debated topic, with proposals including naphtha, quicklime, sulphur, and niter. What set the Byzantine usage of incendiary mixtures apart was their use of pressurized siphons to project the liquid onto the enemy.