Greek fire
Greek fire was an incendiary weapon system used by the Byzantine Empire from the seventh to the fourteenth centuries. The recipe for Greek fire was a closely-guarded state secret; historians have variously speculated that it was based on saltpeter, sulfur, or quicklime, but most modern scholars agree that it was based on petroleum mixed with resins, comparable in composition to modern napalm. Byzantine sailors would toss grenades loaded with Greek fire onto enemy ships or spray it from tubes. Its ability to burn on water made it an effective and destructive naval incendiary weapon, and rival powers tried unsuccessfully to copy the material.
Name
Usage of the term "Greek fire" has been general in English and most other languages since the Crusades. Original Byzantine sources called the substance a variety of names, such as "sea fire", "Roman fire", "war fire", "liquid fire", "sticky fire", or "manufactured fire".History
Incendiary and flaming weapons were used in warfare for centuries before Greek fire was invented. They included sulfur-, petroleum-, and bitumen-based mixtures. Incendiary arrows and pots or small pouches containing combustible substances surrounded by caltrops or spikes, or launched by catapults, were used in the Greco-Roman world. Thucydides mentions that in the siege of Delium in 424 BC a long tube on wheels was used which blew flames forward using a large bellows. The Graeco-Roman treatise Kestoi, compiled in the late 2nd or early 3rd century AD and traditionally ascribed to Julius Africanus, records a mixture that ignited from adequate heat and intense sunlight, used in grenades or night attacks:In naval warfare, the Byzantine emperor Anastasius I is recorded by chronicler John Malalas to have been advised by a philosopher from Athens called Proclus to use sulfur to burn the ships of the rebel general Vitalian.
Greek fire proper was developed in and is ascribed by the chronicler Theophanes the Confessor to Kallinikos, a Jewish architect from Heliopolis, in Syria, by then overrun by the Muslim conquests:
The accuracy and exact chronology of this account is open to question: elsewhere, Theophanes reports the use of fire-carrying ships equipped with nozzles by the Byzantines a couple of years before the supposed arrival of Kallinikos at Constantinople. If this is not due to chronological confusion of the events of the siege, it may suggest that Kallinikos introduced an improved version of an established weapon. The historian James Partington thinks it likely that Greek fire was not the creation of any single person but "invented by chemists in Constantinople who had inherited the discoveries of the Alexandrian chemical school". The 11th-century chronicler George Kedrenos records that Kallinikos came from Heliopolis in Egypt, but most scholars reject this as an error. Kedrenos also records the story, considered implausible by modern scholars, that Kallinikos' descendants, a family called Lampros, "brilliant", kept the secret of the fire's manufacture and continued doing so to Kedrenos' time.
Kallinikos' development of Greek fire came at a critical moment in the Byzantine Empire's history: weakened by its long wars with Sassanid Persia, the Byzantines had been unable to effectively resist the onslaught of the Muslim conquests. Within a generation, Syria, Palestine, and Egypt had fallen to the Arabs, who in set out to conquer the imperial capital of Constantinople. Greek fire was used to great effect against the Muslim fleets, helping to repel the Muslims at the first and second Arab sieges of the city. Records of its use in later naval battles against the Saracens are more sporadic, but it secured victories during the Byzantine expansion in the late 9th and early 10th centuries. Use of the substance was prominent in Byzantine civil wars, chiefly the revolt of the thematic fleets in 727 and the large-scale rebellion led by Thomas the Slav in 821–823. In both cases, the rebel fleets were defeated by the Constantinople-based central Imperial fleet through the use of Greek fire. The Byzantines also used the weapon to devastating effect against the various Rus' raids on the Bosporus, especially those of 941 and 1043, as well as during the Bulgarian war of 970–971, when the fire-carrying Byzantine ships blockaded the Danube.
The importance placed on Greek fire during the Empire's struggle against the Arabs led to its discovery being ascribed to divine intervention. The Emperor Constantine Porphyrogennetos, in his book De Administrando Imperio, admonishes his son and heir, Romanos II, never to reveal the secrets of its composition, as it was "shown and revealed by an angel to the great and holy first Christian emperor Constantine" and that the angel bound him "not to prepare this fire but for Christians, and only in the imperial city". As a warning, he adds that one official, who was bribed into handing some of it over to the Empire's enemies, was struck down by a "flame from heaven" as he was about to enter a church. As the latter incident demonstrates, the Byzantines could not avoid capture of their secret weapon: the Arabs captured at least one fireship intact in 827, and the Bulgars captured several siphōns and much of the substance itself in 812/814. This was apparently not enough to allow their enemies to copy it. The Arabs used various incendiary substances similar to the Byzantine weapon, but were never able to copy the Byzantine method of deployment by siphōn, and used catapults and grenades instead.
Greek fire continued to be mentioned during the 12th century, and Anna Komnene gives a vivid description of its use in a naval battle against the Pisans in 1099. The use of hastily improvised fireships is mentioned during the 1203 siege of Constantinople by the Fourth Crusade, but no report confirms the use of Greek fire. This might be because of the general disarmament of the Empire in the 20 years leading up to the sacking, or because the Byzantines had lost access to the areas where the primary ingredients were to be found, or even perhaps because the secret had been lost over time.
Records of a 13th-century use of "Greek fire" by the Saracens against the Crusaders can be read through the Memoirs of the Lord of Joinville during the Seventh Crusade. One description of the memoir says "the tail of fire that trailed behind it was as big as a great spear; and it made such a noise as it came, that it sounded like the thunder of heaven. It looked like a dragon flying through the air. Such a bright light did it cast, that one could see all over the camp as though it were day, by reason of the great mass of fire, and the brilliance of the light that it shed."
In the 19th century, it is reported that an Armenian called Kavafian approached the government of the Ottoman Empire with a new type of Greek fire he claimed to have developed. Kavafian refused to reveal its composition when asked by the government, insisting that he be placed in command of its use during naval engagements. Not long after this, he was poisoned by imperial authorities, without them ever having found out his secret.
Manufacture
General characteristics
As Constantine Porphyrogennetos' warnings show, the ingredients and the processes of manufacture and deployment of Greek fire were carefully guarded military secrets. So strict was the secrecy that the composition of Greek fire was lost forever and remains a source of speculation. The mystery of the formula has long dominated the research into Greek fire. Despite this almost exclusive focus, Greek fire is best understood as a complete weapon system of many components, all of which were needed to operate together to render it effective. This comprised not only the formula of its composition, but also the specialized dromon ships that carried it into battle, the device used to prepare the substance by heating and pressurizing it, thesiphōn projecting it, and the special training of the siphōnarioi who used it. Knowledge of the whole system was highly compartmentalised, with operators and technicians aware of the secrets of only one component, ensuring that no enemy could gain knowledge of it in its entirety. This accounts for the fact that when the Bulgarians took Mesembria and Debeltos in 814, they captured 36 siphōns and even quantities of the substance itself, but were unable to make any use of them.
The information available on Greek fire is indirect, based on references in the Byzantine military manuals and secondary historical sources such as Anna Komnene and Western European chroniclers, which are often inaccurate. In her Alexiad, Anna Komnene provides a description of an incendiary weapon, which was used by the Byzantine garrison of Dyrrhachium in 1108 against the Normans. It is often regarded as an at least partial "recipe" for Greek fire:
At the same time, the reports by Western chroniclers of the famed ignis graecus are largely unreliable, since they apply the name to all incendiary substances.
In attempting to reconstruct the Greek fire system, the evidence from the contemporary literary references provides the following characteristics:
- It burned on water; according to some interpretations it was ignited by water. Numerous writers testify that it could be extinguished only by a few substances, such as sand, strong vinegar, or old urine, some presumably by a sort of chemical reaction.
- It was a liquid substance – not some sort of projectile – as verified both by descriptions and the name "liquid fire".
- At sea it was usually ejected from a siphōn, but earthenware pots or grenades filled with it – or similar substances – were also used.
- The discharge of Greek fire was accompanied by "thunder" and "much smoke".
Theories on composition
This view has subsequently been rejected, since saltpeter does not appear to have been used in warfare in Europe or the Middle East before the 13th century, and is absent from the accounts of the Muslim writers – the foremost chemists of the early medieval world – before the same period. In addition, the behavior of the suggested mixture would have been very different from the siphōn-projected substance described by Byzantine sources.
A second view, based on the fact that Greek fire was inextinguishable by water, suggested that its destructive power was the result of the explosive reaction between water and quicklime. Although quicklime was known and used by the Byzantines and the Arabs in warfare, the theory is refuted by literary and empirical evidence. A quicklime-based substance would have to come in contact with water to ignite, while Emperor Leo's Tactica of Emperor Leo VI the Wise indicates that Greek fire was often poured directly onto the decks of enemy ships, although admittedly, decks were kept wet due to lack of sealants. Likewise, Leo describes the use of grenades, which further reinforces the view that contact with water was not necessary for the substance's ignition. Zenghelis pointed out that, based on experiments, the result of the water–quicklime reaction would be negligible in the open sea.
Another similar proposition suggested that Kallinikos had discovered calcium phosphide, which can be made by boiling bones in urine in a sealed vessel. On contact with water it releases phosphine, which ignites spontaneously. Extensive experiments with calcium phosphide also failed to reproduce the described intensity of Greek fire.
Consequently, although the presence of either quicklime or saltpeter in the mixture cannot be entirely excluded, they were not the primary ingredient. Most modern scholars agree that Greek fire was based on either crude or refined petroleum, comparable to modern napalm. The Byzantines had easy access to crude oil from the naturally occurring wells around the Black Sea or in various locations throughout the Middle East. An alternate name for Greek fire was "Median fire", and the 6th-century historian Procopius records that crude oil, called "naphtha" by the Persians, was known to the Greeks as "Median oil". This seems to corroborate the availability of naphtha as a basic ingredient of Greek fire.
Naphtha was also used by the Abbasids in the 9th century, with special troops, the naffāṭūn, who wore thick protective suits and used small copper vessels containing burning oil, which they threw onto the enemy troops. There is also a surviving 9th-century Latin text, preserved at Wolfenbüttel in Germany, which mentions the ingredients of what appears to be Greek fire and the operation of the siphōns used to project it. Although the text contains some inaccuracies, it identifies the main component as naphtha. Resins were probably added as a thickener, and to increase the duration and intensity of the flame. A modern theoretical concoction included the use of pine tar and animal fat.
A 12th-century treatise prepared by Mardi bin Ali al-Tarsusi for Saladin records an Arab version of Greek fire, called naft, which also had a petroleum base, with sulfur and various resins added. Any direct relation with the Byzantine formula is unlikely. An Italian recipe from the 16th century has been recorded for recreational use; it includes charcoal from a willow tree, saltpeter, alcohol, sulfur, incense, tar, wool, and camphor; the concoction was guaranteed to "burn under water" and to be "beautiful".