Greek Fire: The Byzantine Empire’s Secret Weapon

Last updated on March 23rd, 2023 at 04:25 pm

The fire sliced through the sea, stoking the flames of fear in the enemies of the Byzantine Empire. The “liquid fire” —as it was popularly known— and its secrets were so crucial that Emperor Romanos II, the Byzantine emperor who reigned between 959-963 AD, declared that three things must never fall into the hands of the enemy.

The Byzantine Imperial regalia. Any royal princess. And Greek Fire.

Incendiary weapons were not novel inventions during the medieval ages.

Flaming arrows and pots filled with combustible elements were launched by catapults, shot by bow, or simply thrown like grenades.

The Assyrians used weapons like these as early as the 9th century BC. Julius Africanus, the roman historian, aptly described these fiery weapons of destruction:

“…this is the recipe: take equal amounts of sulfur, rock salt, adhesive, thunder stone, and pyrite and pound fine in a black mortar at the midday sun. Also, in equal amounts of each ingredient, mix together black mulberry resin and Zakynthian asphalt, the latter in a liquid form and free-flowing, resulting in a product that is sooty-colored. Then add to the asphalt the tiniest amount of quicklime.

But because the sun is at its zenith, one must pound it carefully and protect the face, for it will ignite suddenly. When it catches fire, one should seal it in some sort of copper receptacle; in this way, you will have it available in a box without exposing it to the sun….”

Despite their effectiveness, no fire weapon could hold a candle to Greek fire, which was far more effective. This “atomic bomb” of the medieval ages helped ensure that the Byzantine empire survived many centuries before its eventual fall in the 15th century.

This article seeks to thoroughly discuss the “liquid fire,” explaining what it was and how it was used, and how this impressive weapon might have been created.

Illustration of Greek Firee being used
Illustration of Greek Fire being used

What was Greek Fire?

Greek Fire was a critical part of the Empire’s arsenal and was used on both land and sea.

However, it should not be confused with the cheap imitation used by Crusaders that shared the same name

The latter consisted of a mixture of saltpeter and turpentine. The original Greek Fire was made with more potent substances, making it difficult to replicate.

Historical accounts alluded to the original crafting and use of the weapon during the reign of Constantine IV Pogantus (668-685).

This refined substance supposedly could not be put out by water, which only seemed to make it burn more fiercely.

It was also known to stick to anything it came into contact with, although it appeared that the Arabians had found a way to counter it by dousing their thick clothes or leather in vinegar.

This stickiness made Greek Fire particularly effective in naval contact.

This fiery concoction could be weaponized in many ways. It could be thrown in pots or shot using handheld or ship-mounted tubes similar to a modern-day flamethrower.

The Inventor And History of Greek Fire

Historical accounts suggest that a Syrian refugee named Callanish of Heliopolis developed the superweapon. Callinicus escaped from Syria —which Muslims had invaded— to Constantinople around 668 AD.

A similar substance was found to have existed long before the ingenious creation of Callinicus. During the first century BC Mithridatic Wars, the kingdom of Pontus used a similar weapon against the Romans.

This original weapon was likely Callinicus’s inspiration, but with his knowledge and intuition, he made it more potent and easier to use.

The effectiveness of this weapon meant its recipe was closely guarded.

Partial recipes, however, have been found by historians. One particular from Anna Komnene’s Alexiad and De Ceremoniis Aulae Byzantinae of Constantine VII Porphyrogenitus noted that Greek fire was made of pine and evergreen trees, as well as flammable resins.

Recent research into Greek fire suggests light petroleum or naphtha was the main ingredient, as well as pitch, sulfur, pine or cedar resin, lime, and bitumen.

These ingredients were also probably sourced from Crimea. Speculation suggests melted saltpeter was mixed into the concoction, while sulfur accounted for the booming noise characteristic of the weapon.

Creating the concoction was obviously a dangerous affair. Distilling the petroleum also implied that they must have used sophisticated tools that are now lost to history.

However, little to nothing is established about the contents of the mixture beyond speculation. The formula was handed down from emperor to emperor for nearly a thousand years before eventually becoming lost in the sands of history.

Further, the weapon’s operation system was thoroughly compartmentalized, with each operator only aware of a small part of how the weapon was used.

It required many people working together, which explains why the Bulgarians were unable to use Greek Fire even after laying their hands on 36 projectors.

Using Greek Fire in Battle

Greek Fire was first used against the Arabs during the first Arab siege of Constantinople when the Byzantine fleet utilized mounted tubes to destroy their Arab fleet and break the blockade.

Emperor Leo III The Isaurian later used Greek fire to break another Arab siege in 717 AD. It was also effectively used against a Kievan Rus invasion during the 10th century.

Deployment of Greek Fire

As mentioned earlier, the primary means of deploying Greek fire was through a tube or siphon. This also allegedly led to the invention of portable projectors by Emperor Leo VI.

Byzantine military manuals show that jars filled with Greek fire and caltrops wrapped in tow and set on fire were thrown by catapults. Also, the Byzantines used pivoting cranes to pour liquid fire upon enemy ships.

During warfare on the ground, the Byzantines used Cheirosiphōnes —a hand siphon—  prescribed by 10th-century military authors.


During naval battles, tubular projectors deployed Greek fire. Anna Komnene’s account describes the fire projectors that were mounted on the bow of Byzantine warships:

                 “As he [the Emperor Alexios I] knew that the Pisans were skilled in sea warfare and dreaded a battle with them, on the prow of each ship, he had a head fixed of a lion or other land animal, made in brass or iron with the mouth open and then glided over so that their mere aspect was terrifying. And the fire which was to be directed against the enemy through tubes he made to pass through the mouths of the beasts so that it seemed as if the lions and other similar monsters were vomiting the fire….”

Other accounts, like the Wolfenbüttel manuscript, have more detailed descriptions regarding the function and composition of the entire mechanism:

“… having built a furnace right at the front of the ship, they set on it a copper vessel full of these things, having our fire underneath. And one of them, having made a bronze rub similar to that which the rustics call a squitiatoria, ‘squirt,’ with which boys play, they spray [it] at the enemy.”

These descriptions led enthusiasts of historical weapons and instruments, John Haldon and Maurice Byrne, to design a hypothetical device consisting of the three essential components of the weapon: a bronze pump that pressurizes the oil, a brazier that heated the oil and the nozzle, covered in bronze and hoisted on a swivel.

However, his design had several faults that posed a danger to the operators, as the pressure that mounted in the weapon could easily make the heated oil explode—a flaw that was never recorded in historical accounts of the Byzantine’s use of the weapon.

Hand-held Projectors

With a modern analog being the modern flamethrower, the hand siphon was extensively used starting in the reign of Emperor Leo VI.

Military historians believe these projectors were used by field armies to destroy enemy formations.

Both Emperors Leo VI and Nikephoros Phokas claimed that these hand projectors contained the same substances as those mounted on the ships. However, Haldon and Byrne believe these projectors were fundamentally different than the larger, mounted versions.


Greek Fire was thrown at enemies in its earliest form via a burning ball wrapped in cloth. This cloth also contained a flask and was fired with a catapult that launched them over 350-450 meters.

The mystery of Greek Fire

Greek Fire has captured the imagination of historians and enthusiasts alike. Though its actual composition remains shrouded in history, Greek Fire is a powerful reminder of the extraordinary ingenuity and resourcefulness that characterized the Byzantine Empire.

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