Greek fire was an incendiary weapon used by the Byzantine Empire from the seventh to the fourteenth centuries. The recipe for Greek fire was a closely-guarded state secret and has been lost to history. 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 The term "Greek fire" has been common in English and most other languages since the Crusades. Original Byzantine sources called the substance a variety of names, such as "sea fire" (Medieval Greek: ), "Roman fire" ( ), "Median 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. During the Siege of Petra (550–551) by the Byzantines, the defenders countered the siege engines by throwing fire pots made of sulfur, pitch, and naphtha. 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.Thuc. 4.100.1 The Graeco-Roman treatise , 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 (Latinized Callinicus), a Jewish architect from Heliopolis, in Syria, by then overrun by the Muslim conquests:
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 , "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, which used 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. Emperor Constantine Porphyrogennetos (), in his book , 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 s and much of the substance itself in 812/814. This was apparently not enough to allow their enemies to copy it (see below). The Arabs used various incendiary substances similar to the Byzantine weapon, but were never able to copy the Byzantine method of deployment by , 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 Empire's general disarmament in the 20 years leading up to the sacking, or because the Byzantines had lost access to the areas where the primary ingredients were found, or perhaps even 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 Jean de 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. Adjarian, Hrachia. [The role of Armenians in the Ottoman Empire]. Banber Erevani Hamalsarani 1967; trans. in Charles Issawi, The Economic History of Turkey, 1800–1914, Chicago: University of Chicago Press, 1980, p. 64.
Manufacture
General characteristics
As Constantine Porphyrogennetos' warnings show, the ingredients and the processes of the 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, the projecting it, and the special training of the 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 s 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 describes an incendiary weapon 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:Scott, James Sibbald David (1868). The British army: its origin, progress, and equipment. p. 190.
At the same time, the reports by Western chroniclers of the famed 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 , 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".Leo VI, Tactica, XIX.59, transl. in
Theories on composition The first and, for a long time, most popular theory regarding the composition of Greek fire held that its chief ingredient was saltpeter, making it an early form of gunpowder. This argument was based on the "thunder and smoke" description, as well as on the distance the flame could be projected from the , which suggested an explosive discharge. From the times of Isaac Vossius, several scholars adhered to this position, most notably the so-called "French school" during the 19th century, which included chemist Marcellin Berthelot.
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; it 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 -projected substance described by Byzantine sources.