The Poisoner’s Privilege: How a Gaulish Woman Became Rome’s Deadliest Professional

Locusta of Gaul turned botanical knowledge into a deadly trade.

The narrative that women’s work is a modern invention is a historical fantasy. Since the dawn of society, women have labored—not for fulfillment, but for survival. In Ancient Rome, as in most pre-industrial societies, a woman’s domain was predominantly the domus: the home. Here, she toiled as wife, mother, manager, cook, and weaver. Her work was essential yet invisible, rarely conferring financial independence or social elevation. True, there were exceptions—the merchant, the midwife, the priestess—but these paths were narrow. For most, respect and remuneration were confined within the household’s walls.

Then there is Locusta of Gaul. Her story is an unsettling exception that proves a darker rule. In a society that legally and culturally restricted women’s public roles, Locusta carved a career of infamy. She became a professional poisoner, a state-sanctioned murderer for the Julio-Claudian dynasty. Her tale is not one of empowerment, but of a brutal negotiation with power itself. It forces us to ask: in a world that systematically marginalized women, what did “work you’re respected for” look like at its most extreme? The answer is written in poison, betrayal, and a very short-lived victory.

From Gaulish Herbs to Roman Ambition: The Making of a Mercenary

Locusta’s origins are shrouded in the mist of the provinces. Her name itself—Locusta, meaning “locust”—suggests a pejorative nickname, branding her as a plague upon Rome. Hailing from Gaul (modern France), she likely possessed a deep, practical knowledge of local flora, understanding both the medicinal and lethal properties of plants like belladonna, hemlock, and aconite. This was not uncommon knowledge; folk botany was often women’s domain. What set Locusta apart was her decision to monetize the deadly side of this expertise in the empire’s capital.

How did a Gaulish woman arrive in Rome? The shadow of the slave trade looms large. Julius Caesar’s conquest of Gaul a century prior had flooded Italy with enslaved peoples. It is plausible Locusta arrived in chains, her knowledge becoming a commodity for a master. Alternatively, she may have migrated, a free woman seeking fortune in the sprawling, anonymous metropolis. Rome in the 1st century CE was a pressure cooker of ambition, where the senatorial elite jockeyed for position under the wary eye of the emperor. In such an environment, as our source material notes, “everyone had plenty of enemies.” Locusta identified a market need: discreet elimination.

Her initial operations were successful enough to attract not just clients, but the attention of the law. She was imprisoned, condemned for poisoning—a fate that should have been the end of her story. But in a twist of fate, her notoriety became her resume. Word of her unique skills reached the highest echelons of power: the Palatine Hill and the desperate ears of Empress Agrippina the Younger.

The Imperial Client: Agrippina and the Murder of Claudius

Agrippina the Younger stands as one of Roman history’s most formidable political operators. Sister to Emperor Caligula, wife to Emperor Claudius, and mother to Emperor Nero, her life was a masterclass in dynastic maneuvering. By 54 CE, her goal was clear: to ensure her son Nero, not Claudius’s biological son Britannicus, succeeded to the throne. The obstacle was her aging husband. As the historian Tacitus records, she “had long decided on the crime” of murder and sought “some rare compound which might derange his mind and delay death” to avoid suspicion.

She turned to the imprisoned expert, “Locusta, a person skilled in such matters.” This partnership between the empress and the poisoner is a fascinating sociological moment. Agrippina, operating within the accepted (if ruthless) sphere of matronly influence over family destiny, reached outside the system to a woman whose expertise existed in the criminal underworld. It was a collaboration across social chasms, united by a shared objective.

The assassination of Claudius, as related by Tacitus and Cassius Dio, reads like a dark farce. The first dose, administered via his favorite mushrooms, failed to kill. The ever-cautious Claudius attempted to induce vomiting with a feather—a standard Roman anti-poison measure. Unbeknownst to him, Locusta had anticipated this, and the feather itself was poisoned. The emperor died, and Nero was proclaimed. Locusta’s work had altered the course of the Roman Empire. For her services, she was presumably spared execution, but her true patron was about to change.

The Emperor’s Craftsman: Nero and the Perfection of the Art

Nero’s reign began under his mother’s shadow, but he soon chafed at her control. A more immediate threat was Britannicus, Claudius’s son, who was coming of age and presenting a legitimate rival for popular and political support. Nero needed him gone, and he knew where to find the right tool.

He summoned Locusta, who was, according to Tacitus, still “under sentence.” Nero’s demand was specific: a poison that was both fast-acting and undetectable to a food taster. The first attempt failed. In a rage, Nero “flogged Locusta with his own hand” and ordered her to test new formulas on slaves—a horrifying glimpse into the expendability of life in their pursuit of a perfect murder. The final scheme was diabolically clever. At a banquet, Britannicus was given overly hot, but harmless, wine. His food taster sipped it and was fine. When Britannicus called for cold water to cool it, the accompanying servant (in Nero’s pay) added water from a poisoned carafe. The prince drank, gasped, and fell dead. Nero calmly announced it was merely an epileptic seizure.

This successful murder cemented Locusta’s position. Nero pardoned her past crimes, granted her vast estates, and bestowed upon her the unofficial title of “Imperial Poisoner.” He even sent students to her, institutionalizing her knowledge. For a time, Locusta thrived. She had transcended the fate of a common criminal or a domestic laborer. She was a respected professional—feared, certainly, but also protected and rewarded by the state’s highest authority. Her work had financial reward, social notoriety (a twisted form of respect), and a chilling purpose.

A Woman’s Weapon? Gender, Power, and the Sociology of Poison

Why was poison so readily associated with women like Locusta and Agrippina? From a cultural psychology and gender studies perspective, poison was the quintessential “woman’s weapon” in the Roman mind. It required no physical strength, could be administered secretly within the domestic sphere (the kitchen, the bedroom), and relied on knowledge of herbs and potions—areas often linked to women’s work. The Roman ideal of masculine conflict was open, violent, and honorable: battlefields and duels. Poison was covert, intimate, and dishonorable.

Thus, Locusta’s career was enabled by, and also reinforced, gendered stereotypes. Male emperors used her as a tool to achieve ends while maintaining a facade of clean hands. Her existence allowed historians like Tacitus and Suetonius to doubly condemn Nero: not only was he a murderer, but he did so using the most unmanly and deceitful methods, relying on a woman to do his dirtiest work. Locusta’s infamy served a political and moral purpose in the historical record: she became a symbol of the corruption and feminized decay of Nero’s court.

Was she a serial killer? The modern term is anachronistic, but the pattern fits if we define it as repeated unlawful killing. However, her motives appear purely mercenary, not compulsive or psychopathic. She was a contractor, not a predator. This distinction is crucial. Locusta can be seen as a extreme case of occupational specialization in a violent marketplace. Her psychology was likely that of a pragmatic survivor in a brutal system, leveraging her only asset—deadly knowledge—to climb from prisoner to courtier.

The Brief Payoff: Why Crime (Temporarily) Paid

Locusta’s story brutally illustrates the precariousness of power derived solely from service to a tyrant. For nearly a decade, she enjoyed imperial favor. But her entire world was tethered to Nero’s stability. When the emperor’s excesses sparked revolt and he was declared a public enemy by the Senate, the foundation crumbled. Nero fled and committed suicide in 68 CE (ironically, without using her poisons).

The new emperor, Galba, moved swiftly to legitimize his rule by purging Nero’s apparatus. Locusta, as a notorious symbol of the previous regime’s depravity, was a prime target. Cassius Dio records her fate: she was paraded in chains through Rome—a public humiliation that reversed her social elevation—and then executed. The estates, the pardon, the title: all vanished. Her professional success was entirely non-portable; it died with her patron.

The grotesque myth that she was raped to death by a trained giraffe, while almost certainly apocryphal, speaks volumes about how her story was remembered: as a bizarre and fittingly unnatural end for a woman who had so unnaturally transgressed societal boundaries.

Conclusion: Labor, Agency, and a Legacy Written in Poison

Locusta of Gaul defies easy categorization. She was neither a passive victim nor a feminist icon. She was a woman who, through a confluence of skill, circumstance, and ruthless opportunism, turned a domestic, feminine knowledge into a career of spectacular and terrible public consequence. Her work was respected in the sense that the most powerful people in the world depended on it, paid for it, and feared it.

Yet, her story ultimately reinforces the constraints of her era. Her power was entirely derivative, her safety contingent on the whims of unstable men. She rose high, but her fall was total and brutal. In the long arc of women’s history, Locusta is a dark footnote, a reminder that outside the sanctioned roles of wife, mother, and homemaker, the paths to recognition were few and often led to a dead end—sometimes literally.

She forces us to reconsider what “work” means. Is it only that which builds and nurtures? Or does it also encompass the skilled application of knowledge, however destructive, in service of a demand? Locusta’s profession was homicide, but her career trajectory—apprenticeship, client service, professional recognition, and even teaching—mirrors that of any specialized artisan. The product just happened to be death. In the end, her tale is a grim lesson: in a system that offers women few legitimate avenues for advancement, the illegitimate ones may glitter, but they are almost always lined with poison.