The supremacy of the byzantine navy was undoubtedly due to the existence of greek fire, also known as "see fire" or "Median fire", which was the more refined version of martial incendiary materials existed until then. Ever since the antiquity many flammable materials had been used against the enemy. But the element that made the greek fire unique, making it thus a deadly weapon, was the fact that it didn't extinguished when it came in contact with water.

The Greek-Syrian architect Callinicos is considered to be the inventor of the greek fire. With this he equipped the ships that successfully defended Constantinople against the Arabs in 717-718. Callinicos' contribution probably lies to the optimization of the way the fire was thrown. It's composition remains a mystery even to this day, since both the ingredients and the method of preparation were a state secret. The fear of anathema and the punishments that awaited whoever revealed the secret formula were great. Presumably, the greek fire was a mixture of naphtha and sulfur, while components such as lime, resin and other  combustible material enhanced its possibility of ignition. Natural sources of naphtha could be found in the area between the Caspian and Black Sea, and in Arabia.

The Arabs, just like the Byzantines, had also discovered and successfully used incendiary mixtures using as main ingredients naphtha and liquid tar, that did not put out with water, only sand. The continuous contact between the two countries, combined with the competitions and spying, makes rather unlikely the existence of "secret" weapons, like greek fire.

The liquid fire was kept within oblong clay or metal vessels, called "sifones". They were thrown through special machines found on the prows of ships. These machines functioned rather like crossbows, ie large wood constructions with a mechanism similar to that of the arc that threw stones or arrows. There were also "cheirosifones" who may have been small clay or metal pots filled with greek fire, which would be thrown against the enemies· their function would be similar to that of the current grenades.

The greek fire was mainly used in naval battles. Its  main success was that it brought confusion and panic in the hostile fleets, as it made them flee because of the fire and the bad effect that it had on the morale of the  ship crews. The greek fire was in use by the Byzantines mainly up to the 13th century.