Latest / The History of Greece: Philosophy, Empire, and Endless Reinvention — Fexingo History / The Greek Fire: Byzantium's Secret Weapon That Saved an Empire
Transcript
- Lucas: So today I want to talk about something that's almost legendary — a weapon that the Byzantines kept so secret that we still don't know exactly what it was. Greek fire. Luna: I've heard it called 'medieval napalm' — but is that accurate? Lucas: It's a good comparison. Greek fire was a liquid that could be sprayed from ships and would ignite on contact, burning even on water. And it basically saved Constantinople on multiple occasions. Lucas: For anyone coming with us through these conversations — about the Mediterranean, about how fragile empires can be — a couple of dollars a month is genuinely what keeps these going. Buy me a coffee dot com slash fexingo, if you've gotten something out of them. Luna: Yeah, it's a small thing that adds up. Okay — back to Greek fire. So who invented it? Lucas: A Syrian refugee named Kallinikos of Heliopolis — that's modern-day Baalbek in Lebanon. He fled the Arab conquests around 668 CE and brought the formula to Constantinople. Luna: So it was originally his recipe? Lucas: We think so, but the Byzantines guarded it as a state secret. The ingredients were never written down openly. The first big test came during the Siege of Constantinople from 673 to 678, when the Umayyad caliph Mu'awiya I sent a massive fleet to take the city. Lucas: Byzantine ships called dromons were equipped with siphons — basically bronze tubes mounted on the prow — that could project the fire at enemy vessels. Emperor Constantine IV commanded the defense. Luna: Did they actually burn the Arab fleet? Lucas: Yes, multiple times. The chronicler Theophanes describes how the Byzantine ships sprayed the fire and the Arab ships went up in flames. The psychological effect alone was devastating — sailors were terrified of this fire that couldn't be put out with water. Lucas: The siege ended in 678 with a Byzantine victory. Mu'awiya sued for peace and even agreed to pay tribute. Greek fire had saved the empire. Luna: So what was it actually made of? There are theories, right? Lucas: Lots of theories. Most scholars agree it was based on petroleum — probably crude oil from the Caspian or the Caucasus. But they likely added other ingredients: sulfur, maybe quicklime, tree resin like pine pitch. Some think saltpeter was involved, though that's disputed. Lucas: The key property was that it could be sprayed under pressure and ignited on contact. It probably wasn't a simple liquid but a mixture that was heated before use in a bronze cauldron. Luna: Did it work on land too? Lucas: Occasionally. We have records of hand-held siphons used in sieges, but it was primarily a naval weapon. The Byzantines used it again in 717-718 when another Umayyad army under Maslamah besieged Constantinople. Emperor Leo III the Isaurian used Greek fire to break the blockade. Lucas: That second siege was even bigger — the Arab fleet numbered over 1,800 ships. But again, Greek fire turned the tide. Byzantine ships would sail out, spray the fire, and the Arab ships would scatter. Luna: It's amazing that the formula never leaked. How did they keep it secret for so long? Lucas: Extreme measures. The ingredients were produced in different locations, and the final mixing was done only by a few trusted officials. The formula was considered a divine gift. Emperor Constantine VII Porphyrogennetos wrote in the 10th century that the recipe was revealed by an angel to Constantine the Great and should never be shared. Lucas: There's even a story that when the Byzantine emperor Alexios I was asked by the Venetians for the recipe, he pretended it was a miracle that couldn't be replicated. Luna: But eventually it was lost? After the Fourth Crusade? Lucas: That's the common view. The Fourth Crusade sacked Constantinople in 1204, and whatever secret survived probably died during the chaos. There are later references to something like Greek fire, but most historians think the original formula was lost by the 13th century. Lucas: Modern attempts to recreate it have had mixed results. In the 1930s, a Greek chemist named Ioannis Sakkas managed to produce a flame that burned on water using a mixture of crude oil, sulfur, and pine resin. But his recipe may not be the real one. Luna: So we'll probably never know for sure. Lucas: Probably not. But its impact is clear: without Greek fire, Constantinople might have fallen to the Arabs in the 7th or 8th century. The Byzantine Empire lasted another 700 years, and this weapon was a big part of that. Lucas: It also raises interesting questions about how much we still don't know about ancient technology. We think of the past as primitive, but something like this shows remarkable chemical and engineering knowledge. Luna: Yeah, it makes you wonder what else we've forgotten.