Greek Fire

Greek Fire, a gelatinous, incendiary mixture, used in warfare before gunpowder was invented. Flammable liquids had long been in use, but it was not until the 7th century that Greek fire was invented, possibly by Callinicus, an Egyptian architect who had fled from Syria during the Muslim invasions. Greek fire was an effective weapon, especially when used against ships at sea. The substance apparently ignited spontaneously, and could not be extinguished by water. In 673 Greek fire was used by the Byzantine Empire to repel an Arab fleet attacking Constantinople (present-day İstanbul); the Byzantine Empire continued to use Greek fire in combat until the empire's fall in 1453.

The formula of Greek fire was closely guarded as a state secret for many centuries by the Byzantine Empire. The exact composition of Greek fire is still disputed, but it was probably composed of a mixture of flammable materials such as sulfur and pitch in a petroleum base. This jellylike mixture was sprayed on the enemy from tubes through which it was forced under pressure by pumps.