Although the wielder was on the opposite side, Monty Python was closer to the truth than they realized when they alluded to the Holy Hand Grenade of Antioch. Chemical traces on a ceramic vessel discovered in Jerusalem, which is thought to date from the 12th century, indicate that it formerly held explosives. The vessel was most likely a medieval hand grenade, most likely hurled by Saladin’s army during the Siege of Jerusalem in 1187 CE.
The discovery backs up reports that hand-held explosive devices were utilized during the Crusades, but only in the Middle East and North Africa. Ceramic jars with spherical and conical shapes ranging from the ninth to the fifteenth centuries have been discovered all across the Middle East, but their functions are unknown. They may have stored mercury for mining and therapeutic uses (assuming it didn’t drive you insane), beer, and fragrant oils, according to rumors.
Dr. Carney Matheson of Griffith University examined remnants within four of these jars, all of which were discovered in a stratum dating from the 11th and 12th centuries in Jerusalem’s Armenian Gardens. In a paper published in PLOS ONE, Matheson, ceramicist Rob Mason, and co-authors find that each vessel has a varied chemical make-up, indicating that they may have had a variety of purposes.
Sherd 737, the most important of the four, contains a volatile composition that was almost certainly used as an explosive. Rather than being an import from China, where gunpowder has been used since the ninth century, it appears that this explosive was made in the United States, and probably invented there. Sulfur, mercury, magnesium, and nitrates were found in Sherd 737, indicating that it was a complex explosive device unlike the black powder that was about to arrive from China. For example, the magnesium might have originated from the Dead Sea, where it was mined at the period.
“These boats were described as grenades fired against Crusader castles during the Crusades, causing tremendous sounds and blinding flashes of light,” Matheson said in a statement. “Some experts speculated that the jars were grenades containing black powder, an explosive devised in ancient China and believed to have reached the Middle East and Europe by the 13th century.” It’s been suggested that black powder was imported to the Middle East much earlier, maybe as early as these vessels from the 9th-11th centuries.”
IFLScience spoke with Matheson. Recipes for explosives abound in Arabic writings from the time, but they have proven difficult to duplicate. “These were secret weapons,” he explained, “and they didn’t necessarily want to tell everyone how to build them.” Modern translations are not always accurate, and each recipe is unique. Some recipes ask for dolphin fat, which Matheson believes might be a ruse to make the process appear more complicated than it was when sheep fat would suffice. “If you blended Dead Sea salts and urine [with plant and animal lipids] you’d get something like what we observed,” Matheson told IFLScience based on what he discovered on sherd 737.
Burning arrows have been used to set fires in enemy fortifications for thousands of years, and sulfur has been used since at least 429 BCE. However, Matheson believes that these ceramics were more than just fire starters. Some of them were resin-sealed. They were extraordinarily sturdy due to the strength of the ceramic, which was fired at temperatures of up to 1,300oC (2,400oF), significantly higher than the temperatures used for most pottery. “We anticipate the pressure inside might build up until it explodes in shards,” Matheson told IFLScience, amplifying the effect.
