The real secret to Greek fire was the Byzantine's unusually advanced "siphon," which heated the mixture in a pressure vessel to allow it to spray fairly long di

The real secret to Greek fire was the Byzantine's unusually advanced "siphon," which heated the mixture in a pressure vessel to allow it to spray fairly long distances. The main use was on ships of course, but there was also a man-portable flamethrower version, which is quite strange to think about someone in AD 900 wielding. This ship-borne version only worked in calm conditions, otherwise fireships were just as likely to set themselves on fire. However, it did do pretty well in the sheltered Sea of Marmara around Constantinople. The fireships probably saved the empire from the Caliphate during the 719 siege of Constantinople by destroying the much large Muslim fleet. That occurred at a nadir of Byzantine power and the height of Caliphate power. Western Eurasian history would have looked very different if the Caliphate got control of the Bosporus then, as opposed to the Turks 700 years later.