The discovery of fire which probably came about when a bolt of lightning hit a tree and set it alight has been a positive boon for the human race to move forward. Fire meant that food could be cooked and groups of Homo Sapiens could keep warm during cold winters. But, fire was also adapted to be a weapon of war. It is thought that the Chinese may have been the first to use it as such. But, the one we are going to look at here, is what was called Greek Fire.

It is thought to have first appeared toward the end of the seventh century around the city of Constantinople which is now named Istanbul in modern-day Turkey. The city at this time was Byzantine, with the majority of the population speaking Greek. This incendiary weapon must have been terrifying to those who were the first witnesses and victims of it.
It was used on both land and water. To this day, we do not know for sure what compounds make up this weapon. There are reports that it would burst into flames when it entered water. This would have been a major problem for enemy fleets. It could also be emitted by siphons which meant that the soldiers using it could keep a safe distance from the enemy. To the best of my knowledge, it is believed the incendiary compound was made up of naphtha and quicklime. Another aspect of this weapon was that once on fire, it was difficult to put out.
The secret of this liquid fire was passed down from Byzantine to Byzantine. Even though the enemy captured some of the mixture, they still could not analyse exactly what it was. It remained a formidable weapon for the next several centuries until it was either overtaken by new weapons or the secret formula was lost. We do not know.