Locusta: The Woman Who Poisoned an Empire

The Crime

The year is 54 AD, and the Emperor Claudius is dining with his family.

By most accounts, the meal is lavish — as all imperial meals were. Multiple courses, reclining guests, the finest food Rome could offer. Slaves moved silently between the klinai — the low couches Romans reclined on to dine — carrying platters of food and pitchers of wine. At the center of the table: mushrooms. Specifically, a dish of boleti, a prized variety considered among the finest delicacies in Rome. Claudius was known to love them.

He ate. He became ill. By morning, he was dead.

The official story was sudden sickness. The whispered story — repeated by historians Tacitus, Suetonius, and Cassius Dio — was murder. The suspected architect: his wife, Agrippina the Younger, who wanted her son Nero on the throne before Claudius could change his will. The suspected weapon: poison, introduced into the mushrooms Claudius loved most.

The suspected compound was belladonna — Atropa belladonna — a plant whose extracts had been used in Roman murders long before Locusta. The previous empress, Livia, was rumored to have used the same substance against her own enemies. Belladonna’s active compounds, hyoscyamine and scopolamine, could cause hallucinations, paralysis, and death; their effects and dosages were documented by the 1st-century physician and botanist Pedanius Dioscorides, who called the plant strychnos manikos. It was not obscure knowledge. It was the poison of choice for people who knew what they were doing.

The mushrooms were not prepared by Agrippina’s hand. They were handled by Halotus, Claudius’s own food-taster — the man whose entire purpose was to ensure the emperor’s food was safe. Whether Halotus was complicit or deceived, the sources don’t say. What they record is that the poison appeared, at first, not to work. When Claudius’s condition seemed to stabilize, his physician Gaius Stertinius Xenophon was called. According to Tacitus and Cassius Dio, Xenophon finished the job — inserting a feather coated in fast-acting poison down the emperor’s throat, ostensibly to induce vomiting. Claudius died shortly after.

Ancient sources would later connect Locusta’s name to the mushrooms — though none name her directly in Claudius’s death. Her involvement is inference, built from what came next.

The Poisoner

Locusta had already been convicted of poisoning before Agrippina came to her. She was sitting in prison awaiting execution when she was offered something better: immunity, in exchange for her services to the imperial family.

She accepted.

What followed was a career that would make her the most infamous woman in Roman criminal history. Whether or not she had a hand in Claudius’s death, she was soon called on again. Nero needed her to eliminate Britannicus, Claudius’s biological son and the one person who could challenge Nero’s claim to power. When the first attempt failed — Britannicus vomited the poison, which had been served too hot and diluted — Nero personally oversaw Locusta’s second attempt. He reportedly tested it on a pig in front of her, watching how quickly the animal died, and sent her back to try again.

The second attempt, administered in a cold drink at a dinner Britannicus attended, worked within minutes. According to Suetonius, Britannicus collapsed at the table. The other guests were told he was having an epileptic episode. Dinner continued.

Nero rewarded Locusta with a full pardon, estates, and students — she ran what amounted to a school for poisoners under imperial protection.

She remained useful to Nero until the very end. Before he fled Rome in 68 AD, he obtained a final supply of poison from her and had it sealed in a golden box, kept on his person. He intended it for himself. He died by other means.

Her end came with Nero’s. When Nero fell, Locusta lost her protector. The new emperor Galba had her arrested along with Nero’s other inner circle — Helius, Patrobius, Narcissus, and what Cassius Dio called “the scum that had come to the surface in Nero’s day.” They were led through the streets of Rome in chains, a public spectacle of the old regime’s corruption, before being executed.

She had operated for nearly fifteen years at the highest levels of Roman power. Her weapon was never a sword. It was always the food.

The Table as Crime Scene

What made Roman dining so perfectly suited to poison?

Everything was shared. Romans ate communally, reclining on couches around a central table, taking food from shared platters with their hands or small spoons. There were no individual portions, no separate plates in the modern sense. A poison introduced into a dish could be targeted — or made to look accidental.

The gustatio, or appetizer course, typically included eggs, olives, salted fish, and vegetables. The prima mensa, the main course, was where the spectacle happened — roasted meats, stuffed dishes, elaborate preparations designed to display the host’s wealth. The secunda mensa brought sweetened wines, fruit, and nuts.

Mushrooms appeared across all courses. They were considered so fine that the Emperor Nero reportedly called them the “food of the gods” — a phrase that took on darker meaning after Claudius died eating them.

Poison could be introduced at any point. In the food itself. In the wine. In the water used to dilute the wine.

The line between Roman cuisine and Roman crime was thinner than you think.

 

Sources & Notes

Locusta is named directly in Tacitus, Annals XIII.15, in connection with the death of Britannicus. Her connection to the death of Claudius is not directly attested in the sources we have — it is an inference drawn from her subsequent role under Nero and Agrippina. Tacitus covers Claudius’s death in Annals XII.66-67 without naming her; the Xenophon detail appears there and in Cassius Dio 61.34. The details surrounding Nero — the pig, the pardon, the school of poisoners, and the golden box — come primarily from Suetonius (Life of Nero, §33 and §47) and should be read as ancient reportage rather than confirmed fact. Suetonius wrote decades after the events and had a taste for the dramatic. Cassius Dio (Roman History, LXI and 63.3.4) provides additional context, including the account of Locusta’s public execution under Galba. All three sources had political motivations that color their accounts — painting Nero and Agrippina as monsters served a narrative purpose. That doesn’t make Locusta fictional. It means the details deserve scrutiny.

The Roman poet Juvenal also mentions Locusta in Satires Book 1, line 71, using her name as shorthand for a master poisoner — evidence that within decades of her death, she had become a byword for the craft.

The belladonna identification draws on Pedanius Dioscorides, the 1st-century Greek physician and botanist whose De Materia Medica documented the plant’s toxic properties and doses. He called it strychnos manikos.

Primary sources available free at Perseus Digital Library and LacusCurtius. Apicius at Project Gutenberg.

1.  Juvenal (1839). Juvenal and Persius, Volume 1. Martin Madan (trans.). J. Vincent. p. 21.
2.  Scholiast on Juvenal 1.71.
3.  Tacitus, Annals 12.66-67; Cassius Dio 61.34.
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6.  Suetonius, Nero 33; Tacitus, Annals 13.15.
7.  Suetonius, Nero 47.
8.  Cassius Dio 63.3.4
9.  Juvenal, Satires 1.71.
10.  Dumas, Alexandre. The Count of Monte Cristo. Oxford, GBR: Oxford University Press, UK, 2008. ProQuest ebrary. Web. 10 November 2015.
11.  Malthête, Jacques; Mannoni, Laurent (2008). L’oeuvre de Georges Méliès. Paris: Éditions de La Martinière. p. 229. ISBN 9782732437323.
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