Greek fire was a weapon that secured countless victories for the Byzantine Empire during its battles. The first recorded use of Greek fire dates back to the first siege of Constantinople in 674, where the Arab Muslims were halted at the gates of the capital thanks to the use of this weapon. It was later used to repel them again during the second siege in 717. The Byzantine historian Theophanes the Confessor attributes the invention of Greek fire to Kallinikos in the 7th century. Its formula remains secret to this day, and it is not well known what type of materials were used to create it. It was, in fact, a highly flammable liquid that was launched at enemy ships. The unique characteristic of the compound was that it could not be extinguished by water, which instead fueled the fire. The Byzantines themselves called it "liquid fire," as the term "Greek" is not found in Byzantine sources. However, it is likely that the liquid was composed of materials readily available at the time in the Caucasus region, such as petroleum, naphtha, sulfur, and plant resin.

Greek fire had a versatile range of uses: it could be stored in small jars that were used as rudimentary grenades or in large barrels that were launched via catapults. However, its most famous use was as a primitive flamethrower. This device was actually a siphon that was mounted on both the stern and bow of ships. Once the ships were close enough to the enemy vessels, the fire was shot by operators, known as "siphonators." The fire would last only a few seconds but had a range of about fifteen meters. The use of Greek fire is documented up until the Third Crusade, after which its production likely ceased, both due to the inherent danger in its creation and the gradual depletion of the raw materials needed to produce it.