Greek fire was a substance that, though the name is “Greek Fire” and it was most likely originally developed by the Greeks, it was used mainly by the Byzantium Romans. One of it’s many names was “liquid fire” and was used by spraying out a nozzle onto enemy ships or soldiers. It was especially effective at sea, as the Roman’s navy was generally not as powerful or as skilled as the enemy navies they came across, so the greek fire was a great advantage.
When it was sprayed onto an enemy ship, it would ignite as it came out of the Roman nozzle, sticking to the wooden ships of the enemy and the crew manning it while still ignited. Greek fire burned so fiercly, it would not go out even when submerged underwater, so the victims of this fire were very unfortunate even when they jumped overboard hoping the fire would be extinguished. Not only was it sprayed out at sea, but on land it was put into small clay pots and used as grenades, probably being lighted just before it was tossed into enemy lines. Also large jars of it were used in catapults, possibly bursting into flame because of the friction upon impact.
There are still, even today, very many mysteries about greek fire. As you may have noticed, I have used a few words such as “possibly” and “probably”. This is because as we do have tapestries and pot paintings that have pictures of greek fire being used in catapults, grenades, and sprayed through nozzles onto enemy ships, the Byzantiums kept the compostion details and the mechanisms on the ships a very closely guarded secret, so guarded that no recipes have survived today, that we know of. We can take a guess though.
Due to the sticking onto things, and to help in the burning, a good deal of Sulfur was probably used, as it melts in the heat of a flame, but is still gooey enough to stick onto things. And people. Also it burned pretty well and, of course, stinks. Meaning the smell (mixed with Hydrogen it becomes a poisonous gas, found in rotten eggs). Some type of gasoline was very probably the primary ingredient, as in burns fiercly and is found plentifully around the black sea in numerous wells. Beyond these ingredients, people are not really sure of the recipe, but maybe it’s a good thing that we don’t know, as some of my younger readers may try it at home.