- Archeologists analyzed the residue inside four ceramic vessels found in the Old City of Jerusalem.
- One vessel was potentially a medieval grenade, consistent with first-hand accounts from the period.
- It contained the remnants of an explosive mix of plant oils, animal fats, nitrates, and sulfur.
A new analysis of a medieval ceramic vessel excavated from the Old City of Jerusalem suggests the Crusader knights could have developed rudimentary hand grenades in their wars against the Muslim rulers of the Holy Land.
Archeologists from Griffith University, in South East Queensland, Australia, examined the residue inside four sphero-conical containers.
Three showed evidence of use for various purposes, including holding oils, scented materials, and medicine.
However, inside the so-called Sherd 737 vessel, archeologists found deposits suggesting that ceramic jars were potentially used as handheld explosive devices.
Sherd 737, which has thick walls, no decoration, and indications of a resin seal, had the remnants of the flammable chemical ingredients needed for an archaic explosive device.
The residue, according to the study published in the scientific journal PLOS One, is consistent with what would be required to build a medieval hand grenade.
Previously, researchers assumed that medieval grenades would have contained gunpowder. But gunpowder, first developed in China, did not appear in the Middle East until the 13th century.
The Crusades, a series of religious wars led by European Christians to conquer Jerusalem and the Holy Land from its Muslim rulers, were fought between 1095 and 1291. The vessels are believed to be from the 11th or 12th centuries.
Sherd 737, according to the archeologists, contained traces of a unique explosive mix composed of plant oils, animal fats, nitrates, and sulfur. It suggests that Crusader knights had invented their own blend of explosive chemicals.
"It shows that the explosive weapons described by the Crusaders were a local invention," said Carney Matheson, a molecular archaeologist at Griffith University, in an email to Insider.
"This shows for the first time a whole different mixture for the ingredients of an ancient explosive which is consistent with the historical Arab texts," Matheson continued.
The study is significant, he added, because it "advances our understanding of medieval weapons in the Middle East at this time" and verifies the accounts of the Crusaders.
First-hand accounts from Crusader knights and Arab texts mention the use of handheld devices that exploded with loud bangs and flashes of light, Griffith University said in a statement consistent with these findings.
More research on similar vessels will be needed to further understand the ancient explosive technology used during the medieval period, Matheson said in the statement.