Over on another place, I have been talking to Jean Henri Chandler the fencer and RPG writer about the trope of poisoned weapons. Writers of adventure stories in the 20th century loved this trope. In Robert E. Howard’s “Black Colossus” a beast is defeated with a poisoned dagger, while in Hour of the Dragon a poisoned needle protects a treasure and can kill with a scratch. Tolkien’s Witch-King wields a cursed knife whose wounds cannot be healed by ordinary medicine, and in the Warhammer setting Dark Elves or Dark Eldar love their poisoned daggers and flechette launchers. Brian Jacques’ villain Cluny the Scourge has a poisoned barb on his tail, and Jack White’s Arthurian novels (goodreads) have poisoned needles too.
Fun-ruining historians like me point out that people before the 20th century were often vague on the difference between a wound which was poisoned, infected, cursed, and just hard-to-cure. The French accused the English of poisoning their arrows, but the English said they were mistaking rust or verdigris for poison. Various people who faced early guns insisted that the balls were poisoned, when more likely guns just made a big deep wound and carried scraps of clothing into it. Excitable Romans love accusing foreigners of using poisoned arrows. Many recipes for poisons in books do not actually work, or would have required such great doses that the victim would probably have died from the weapon carrying the poison (although there are many plant-based and chemical poisons in the Old World). So we have to look at each of these stories carefully, and often we will not have good enough evidence to show that something that really happened happened. But when I think about some of the stories I have heard, I can think of some rules of thumb.
Stories about poisoned arrows are common. One of the characters in the Iliad is worried that an arrow was poisoned, and a variety of Greek and Roman writers accuse people living west, north, or east of the Black Sea of using poisoned weapons. It seems to me that when people before the 20th century talk about poisoned weapons, they usually have arrows, crossbow bolts, or darts in mind. Poisoned arrows are attested in so many places, from Ming China to the San in Africa to Slav and Ante country on the Black Sea to Amazonia, that we should not be too skeptical of them. Militia laws from 14th and 15th century Portugal even list envenoming bolts as something which crossbowmen should practice on Sundays. I did not know of many of the sources from the Greek and Roman world until the chat with Jean Chandler.
Poison often seems associated with weak weapons such as Chinese repeating crossbows or small bows used to hunt big elephants. Its also often associated with hunting. Wounded animals tend to run away and can’t treat their wounds as well as humans can. A human soldier who is lightly wounded may keep fighting and kill his attacker or win the battle before the poison takes effect. A murder victim may tell everyone who stabbed him before his wound festers (or go see a doctor and be healthy enough to attend his attacker’s execution). Apparently the Chinese called the poison they applied to crossbow bolts “tiger-killing poison.” When people imagine poisons, they often have then kill in seconds or minutes, whereas real poisons often kill in hours or days. The Roman medical writer Celsus also associated poisoned weapons with hunting rather than war or murder.
On the other hand, I am having trouble thinking of stories about poisoned swords, spears, or daggers before Shakespeare’s Hamlet (c. 1599-1601). There was a story that when Alexander invaded India, he came to a city whose warriors smeared their “swords” or “iron” with a deadly poison (Diodorus 17.103.4-8, Curtius, 9.8.20‑28, Justin, 12.10.1‑3). TvTropes claims that in one version of Tristan and Iseult, Sir Morholt stabs Tristan with a poisoned spear. But those are the only two examples of the trope before Hamlet which I can find.
Do any of my gentle readers know of other early stories about poisoned swords and daggers? I think that before first aid courses and antibiotics, people were scared enough of being stabbed without having to imagine that the weapon was poisoned. But I certainly don’t know everything! I had forgotten about the story of Slavs poisoning their arrows, and not read the passage by Celsus.
Some fun ancient sources about poisoned weapons are Celsus, de Medicina, book 5 chapter 27, and Maurice, Strategikon, book 11, chapter 4. Adrienne Mayor has a big book full of ancient stories about poison, biological weapons, and incendiaries called Greek Fire, Poison Arrows, & Scorpion Bombs: Biological & Chemical Warfare in the Ancient World (Abrams Press, 2008) [Amazon] Around the year 1600, Cheng Zong You wrote a treatise on crossbows with a section on how to make a weak crossbow effective by poisoning the darts (thanks Benjamin H. Abbott for the reference; he also recommended A Cultural History of the Atlantic World, 1250-1820 by John K. Thornton for stories about Europeans encountering poisoned weapons in Africa and the New World).
In the dying days of academic blogs, Michael D. of Unlocked Wordhoard responded to the project which created an effective eye salve from an Anglo-Saxon leechbook with “wow, we tried that and could not get it to work!” A project at the University of Toronto armed with PhDs in natural science, an unlimited materials budget, and unlimited time was unable to make saltpeter strong enough for gunpowder, which people with grade-school educations used to make in rural Kentucky last century. Descriptions of a physical process which let any reader reproduce it are rare, because of implicit knowledge or tacit knowledge and because writing is hard.
 Ferreira, Leandro / Skoog, Martin Neuding (2020) “Crossbowmen in late medieval Portugal and Sweden. A comparison / Besteiros em Portugal e na Suécia em finais da Idade Média. Uma comparação.” População e Sociedade nr. 33 (June 2020) p. 40 https://www.cepese.pt/portal./pt/populacao-e-sociedade/edicoes/populacao-e-sociedade-n-o-33 ↑ back to note ↑
(scheduled 14 July 2022)
Edit 2022-10-26: for another take see https://www.arms-n-armor.com/blogs/news/did-medieval-europeans-use-poisoned-blades They provide a copy of an article which says that the 16th century surgeon Ambroise Parè divides wounds from weapons into poisoned and not poisoned (but no page reference so danger, danger Will Robinson!): “Plant Poisons in Medieval Warfare,” Medical Bulletin of the US Army, Europe Vol. 41 No. 10/11 (1984) pp. 48-53