717 A.D. was a year of acute crisis for the Emperor of Constantinople, Leo III. Skirmishing Muslim armies had seized Anatolia and were swiftly marching on the Holy city itself. The eastern "Rome" would have perhaps fallen to the invaders -- the Muslims were adept at planning a prolonged seige -- if it were not for the use of "Greek Fire." This was an older tactic that had been used by the Greeks hundreds of years before -- yet, it was the scientists inside Constaninople who actually perfected the weapon. They combined a mixture formed of petroleum, sulphur, and saltpeter that ignited on contact with water. This FIRE was crucial in the defense of the city. The Muslims were terrified of the "Sea Fire"... they did not understand how it could actually seem to burn and blur in terrible fury on the waves. Leo III was successful in using this weapon to drive back the Muslims, and Constantinople would be saved. For a long time the actual ingredients of the "Greek Fire" were carefully guarded secrets. Leo III claimed it was "Divine Intervention" in saving the Holy City.