Greek Fire

Greek fire was the most famous secret weapon of the medieval world. Invented by the Byzantine Empire in the seventh century, Greek fire was a flammable liquid that could be projected through tubes onto enemy ships, where it would burst into flames on contact with water. The weapon was the principal defense of the Byzantine Empire against the Arab sieges of Constantinople in the seventh and eighth centuries, and it gave the Byzantines a decisive military advantage for several centuries.

The exact composition of Greek fire has been lost, and the formula remains a subject of intense scholarly debate. The weapon was, however, so important to the survival of the Byzantine Empire that the secret of its composition was closely guarded by the imperial government, and the formula was passed down only within the imperial family and a small group of trusted officials. The loss of the formula, perhaps in the thirteenth or fourteenth century, was a major factor in the decline of Byzantine military power.

The study of Greek fire is, in practice, the study of one of the mysterious military secrets of the medieval world, and it makes sense only against the background of the survival of the Byzantine Empire through the crisis of the seventh and eighth centuries.

The Invention of Greek Fire

The Traditional Account

According to the traditional account, Greek fire was invented in the reign of the emperor Constantine IV (668–685), by a Syrian architect and engineer named Kallinikos (or Callinicus), who had fled from his home in Syria to Constantinople to escape the Arab conquests. The traditional account says that Kallinikos offered the secret of the weapon to the emperor, and that the emperor used it to great effect in the defense of Constantinople against the second Arab siege of 674–678.

The traditional account has been questioned by modern scholars, who have suggested that the weapon may have been developed gradually over a longer period, rather than being the invention of a single person. The modern view is that Greek fire was probably developed by the Byzantine government in the seventh century, in response to the Arab threat, and that the story of Kallinikos is a later embellishment.

Whatever its exact origins, Greek fire was a major innovation in the history of warfare, and it gave the Byzantines a decisive military advantage for several centuries. The weapon was used in both land and sea battles, and it was the principal defense of the Byzantine Empire against the Arab sieges of Constantinople in the seventh and eighth centuries.

The Composition

The exact composition of Greek fire has been lost, and the formula remains a subject of intense scholarly debate. The principal ingredients of the weapon, as reported in the Byzantine sources and in the modern reconstructions, included petroleum (or a similar petroleum-based product), quicklime, sulfur, and saltpeter. The ingredients were mixed in a specific proportion, and the mixture was heated to produce a flammable liquid that would burst into flames on contact with water.

The role of quicklime in the mixture is particularly important, since it is the quicklime that gives Greek fire its most distinctive property: the ability to burn on water. When Greek fire was projected onto water, the quicklime would react with the water to produce a great deal of heat, which would ignite the petroleum and produce a sustained flame. The quicklime also made the fire very difficult to extinguish, since attempts to put it out with water would only intensify the reaction.

The exact formula of Greek fire has been the subject of many modern experiments, and several plausible reconstructions have been proposed. The most commonly cited reconstruction includes petroleum, quicklime, sulfur, and saltpeter, with the proportions adjusted to produce the desired burning properties. None of the modern reconstructions, however, has been definitively accepted, and the exact formula of Greek fire remains a mystery.

The Use of Greek Fire

The Arab Sieges of Constantinople

Greek fire was first used in battle during the second Arab siege of Constantinople in 674–678. The siege, which lasted for several years, was the most serious threat to the Byzantine capital since the founding of the city, and the Byzantines were forced to use every weapon at their disposal to defend the city. Greek fire was the most effective of these weapons, and it played a decisive role in the defeat of the Arab fleet.

The Arab chroniclers of the siege reported with awe the effects of Greek fire, describing how the liquid burst into flames on contact with the water and how the flames could not be extinguished. The Arab commander, Yazid, was reportedly so alarmed by the weapon that he withdrew his fleet from the siege, and the siege was eventually lifted. The use of Greek fire at Constantinople established the weapon as the principal defense of the city, and it was used in all subsequent Arab sieges of the city.

Greek fire was also used in the second great Arab siege of Constantinople in 717–718, which was led by the Umayyad caliph Maslamah ibn Abd al-Malik. The siege was the high-water mark of the Umayyad Caliphate, and it threatened to capture the Byzantine capital and to end the Byzantine Empire. Greek fire was again the principal defense of the city, and it played a decisive role in the defeat of the Arab fleet and army. The failure of the siege marked the beginning of the decline of the Umayyad Caliphate, and it was one of the most important events in the history of the medieval world.

The Naval Battles

Greek fire was also used in naval battles throughout the Byzantine period, and it was the principal weapon of the Byzantine navy. The weapon was projected onto enemy ships through tubes mounted on the bows of the Byzantine ships, and it would burst into flames on contact with the water, setting the enemy ships on fire and causing panic among the crews.

The Byzantine navy used Greek fire to great effect in the battles with the Arab navies in the seventh and eighth centuries, and it was a major factor in the Byzantine control of the Eastern Mediterranean. The weapon was also used in battles with the Russian fleets in the tenth and eleventh centuries, and it was reportedly used in the battle against the fleet of the Russian prince Igor in 941.

The use of Greek fire in naval battles was so important that the Byzantines developed a special class of ships, the dromons, that were designed specifically for the deployment of Greek fire. The dromons were equipped with tubes for projecting the weapon, and they were the most effective warships of the medieval world.

The Secret of Greek Fire

The Imperial Monopoly

The formula of Greek fire was one of the most closely guarded secrets of the Byzantine Empire, and the imperial government took extraordinary measures to prevent the secret from being revealed. The formula was known only to the emperor and to a small group of trusted officials, and the production of Greek fire was carried out in a special workshop in the imperial palace, under the supervision of the imperial government.

The Byzantine emperors also took steps to prevent the secret from being transmitted to foreigners. The foreign ambassadors who visited Constantinople were carefully watched, and the production of Greek fire was carried out in a part of the palace that was off-limits to visitors. The export of the ingredients of Greek fire was forbidden, and the possession of the ingredients by foreigners was a capital offense.

The imperial monopoly on Greek fire was one of the most important secrets of the Byzantine state, and it was the basis of the Byzantine military superiority for several centuries. The monopoly was eventually broken, however, as the formula was gradually leaked to other states, and the weapon was eventually copied by the Arabs, the Russians, and other peoples.

The Loss of the Formula

The exact date of the loss of the formula of Greek fire is unknown, but it is generally believed to have been lost in the thirteenth or fourteenth century, perhaps as a result of the capture of Constantinople by the Fourth Crusade in 1204 or the general decline of the Byzantine state. The loss of the formula was a major factor in the decline of Byzantine military power, and it was one of the most significant events in the history of Byzantine military technology.

The loss of the formula is documented in the Byzantine sources, which report that the secret was gradually forgotten, and that by the fourteenth century, the Byzantines themselves were uncertain of the exact composition of the weapon. The decline of the Byzantine Empire in the fourteenth and fifteenth centuries meant that the resources were not available to reconstruct the formula, and the secret was finally lost.

The Legacy of Greek Fire

The Influence on Other States

Greek fire was widely copied by other states, and the weapon was used by the Arabs, the Russians, the Chinese, and other peoples throughout the medieval period. The Arab copies of Greek fire were used in the battles of the Arab conquests, and the weapon was reportedly used in the Arab conquests of Spain and southern Italy.

The Russian copies of Greek fire were used in the battles of the Russian principalities, and the weapon was reportedly used in the battles of the Mongol conquests. The Chinese copies of Greek fire were used in the battles of the Song and Ming dynasties, and the weapon was reportedly used in the battles of the Mongol conquests of China.

The influence of Greek fire on the development of military technology was profound, and the weapon was the precursor of the modern weapons of war, including the flamethrower, the incendiary bomb, and the modern rocket. The invention of Greek fire was, one of the most important developments in the history of military technology.

The Place in Byzantine Culture

Greek fire held a special place in Byzantine culture, and the weapon was the subject of many literary and artistic works. The Byzantine historians of the seventh and eighth centuries wrote about Greek fire with a sense of awe, and they attributed the weapon to the divine protection of the Virgin Mary. The most famous of these accounts is the story of the defense of Constantinople against the Arab siege of 717–718, in which the Virgin Mary allegedly appeared on the walls of the city and protected the defenders.

Greek fire was also celebrated in the liturgy of the Orthodox Church, and the weapon was the subject of a special prayer in the liturgical calendar. The prayer, which is still recited in some Orthodox churches, asks the Virgin Mary to protect the city of Constantinople from its enemies, just as she protected the city in the past with the miracle of Greek fire.

Conclusion

Greek fire is the most famous military secret of the medieval world, and it is one of the few whose chemical formula has remained unrecoverable despite several modern attempts to reproduce it. The version that worked for the Byzantines probably contained a quicklime component, which is the only known way to make a hydrocarbon mixture ignite on contact with water; the rest of the recipe is lost. It is striking, and slightly humbling, that the formula was kept secret for more than five centuries.