Lethal elixirs: notorious poisonings in ancient Roman history
From the earliest decades of the Principate, the use of poison exposed a darker reality behind Rome’s public order, because, while the legions secured borders and the Senate passed decrees, true power often seemed to pass by the removal of one individual at the right moment.
In some circles among the elite, poison became a preferred method of assassination since it eliminated rivals without attracting the scrutiny that followed armed violence.
Roman historians preserved dozens of accounts of heirs who sickened unexpectedly and governors who died abroad, with emperors sometimes dying suddenly after brief illnesses.
Not every case left conclusive evidence, but many deaths seemed to align too neatly with political outcomes to be dismissed as coincidence.
It is worth noting that the Lex Cornelia de sicariis et veneficiis, which was originally passed during the late Republic, formally criminalised poisoning, but enforcement often targeted slaves, or women, while those responsible among the elite often evaded punishment.
1. The Borgia-Like Poisonings of Livia Drusilla
According to multiple sources, Livia Drusilla, who was the wife of Augustus and the mother of Tiberius, was said to have manipulated the imperial succession.
After Augustus had adopted Gaius and Lucius Caesar as his heirs, both died of sudden illnesses (Gaius in AD 4 and Lucius in AD 2) after showing no prior signs of ill health.
Tacitus had implied that these deaths were too convenient for Livia’s plans to ignore.
By removing both adopted sons, she cleared the way for her biological son Tiberius to inherit the throne.
However, modern historians generally attribute these deaths to natural causes, particularly Gaius’ lingering battle wounds and Lucius’ illness while travelling.
Significantly, Livia held close access to Augustus and his inner circle. She controlled domestic arrangements and held influence over imperial staff, which may have granted her ample opportunity to interfere with food, medicines, or messages.
Agrippa Postumus, who had been the only remaining potential heir, was exiled and later killed shortly after Augustus' death in AD 14.
Although some ancient sources implied Livia or Tiberius orchestrated the killing, others suggest Augustus may have ordered it in advance as part of a succession plan.
These accounts, which had been preserved in Tacitus’ Annals (1.3–1.6) and Dio Cassius’ Roman History (Books 55–56), had heightened suspicion among contemporaries that Livia arranged a series of carefully timed killings.
Suetonius relayed a rumour that Augustus died after eating poisoned figs plucked from trees that Livia had tampered with.
Many modern historians doubt the tale’s accuracy, and its popularity in Roman accounts reflects the degree of suspicion surrounding her.
After Tiberius took the throne, the Senate granted Livia the title Augusta and allowed her to retain significant honours.
The deaths that cleared Tiberius’ path occurred in sequence, with timing that continued to arouse suspicion long after Livia’s death in AD 29.
2. The Fall of Germanicus
By AD 17, Germanicus Caesar had become widely admired among members of the Julio-Claudian dynasty.
He had secured victories in Germania, governed provinces in the East, and commanded the loyalty of the Roman army.
Tiberius lacked Germanicus’ popularity and charisma, and he had appointed him to oversee affairs in the eastern provinces, a decision that many interpreted as an attempt to distance him from the centre of power.
Once in Syria, Germanicus had clashed with the governor, Gnaeus Calpurnius Piso, whose open defiance of orders escalated tensions into political hostility, as shortly after these disputes intensified, Germanicus fell ill in Antioch.
His symptoms were violent stomach pains that were followed by sudden fevers and delirium.
They followed the pattern of deliberate poisoning rather than natural disease.
Tacitus had written that Germanicus had discovered cursed objects and human remains in his residence, which Romans associated with witchcraft and deliberate harm.
As his condition worsened, he accused Piso directly and said that Piso had arranged the poisoning to remove him as a threat.
These events are described at length in Tacitus’ Annals (2.69–2.80), though no conclusive proof ever emerged to support the allegation.
Agrippina the Elder, who was Germanicus’ wife, had brought his ashes back to Rome and had stirred public sympathy when she portrayed her husband as a murdered hero.
Piso was recalled to Rome and stood trial in AD 20, but died before the trial concluded.
Officially, his death was a suicide. However, some suspected that Tiberius, eager to silence further inquiry, had orchestrated it.
Regardless, Tiberius grew hostile to Germanicus’ widow and children, and he eventually ordered the imprisonment and death of two sons, while the third was Gaius, later known as Caligula, and he survived long enough to inherit the imperial title in AD 37.
3. The Poisoned Chalice of Britannicus
After the death of Claudius in AD 54, his son Britannicus retained a legitimate claim to the throne.
Yet Agrippina had already positioned her son Nero to succeed, having secured his adoption and marriage into the imperial family years earlier.
At the time of Claudius’ death, Nero had the backing of the Praetorian Guard, the Senate, and the court.
However, Britannicus remained a lingering threat. Though still a teenager, he represented a direct biological connection to the previous emperor and might, as he matured, gather support.
To eliminate the danger before it matured into rebellion, Nero had apparently planned his death during a banquet in AD 55.
Nero instructed his agents to serve Britannicus a cup of wine that had been cooled with poisoned water.
Tacitus had recorded that Britannicus had taken one sip, collapsed, and died before the guests.
Nero claimed that the boy had suffered from epilepsy, though the term was likely used loosely and not as a formal medical diagnosis.
Suetonius’ Life of Nero (33) and Tacitus’ Annals (13.14–17) provide overlapping but distinct versions of the murder.
Locusta, who was reportedly a professional poisoner already employed by Nero, had reportedly prepared the mixture.
Her reputation had grown during the last years of Claudius’ reign, and by some accounts Nero had used her repeatedly and had eventually granted her state protection.
She had allegedly also supplied the poison that killed Claudius himself, according to later accounts, though the evidence relied on indirect signs and varied between sources.
Her involvement in Britannicus’ death helped to confirm to contemporaries Nero’s willingness to use murder as a political solution.
After the banquet, the emperor moved swiftly to remove or silence anyone who questioned his account, and the pattern of quiet eliminations continued for the remainder of his rule.
Locusta remained in imperial favour until AD 69, when Galba had her executed during a purge of Nero’s inner circle, although the exact details of her death remain uncertain according to some accounts.
4. The Murder of Domitian
By the mid-90s AD, Domitian had alienated many senators, courtiers, and members of his household through a campaign that used arrests and executions, and that led to wide purges.
He operated in a climate of fear and became increasingly convinced that plots surrounded him.
His intense fear, whether justified or exaggerated, led some members of his own court to conspire against him.
Parthenius, who served as his chamberlain, led the group and may have first attempted to kill the emperor by poison.
Suetonius claimed that the poison did not kill Domitian outright because either the dose proved too weak or Domitian had developed resistance by consuming antidotes, as many emperors had done as a precaution.
Once the attempt failed, the conspirators turned to violence. On 18 September AD 96, a freedman named Stephanus entered the emperor’s private quarters with a dagger concealed under a bandaged arm.
After a brief struggle, Domitian died from multiple wounds.
Although the successful killing happened with a blade, the possible failed poisoning remained significant.
It suggested that even imperial bodyguards and personal attendants considered poison the safest initial option for regicide.
After Domitian’s death, the Senate erased his name from public records through damnatio memoriae, and Nerva became emperor with Senate support.
However, the conspiracy suggested how far discontent had spread, and how poison remained a preferred method when subtlety still seemed possible.
Beware the Romans...
Those who controlled the kitchens, who guarded the medicine, or who arranged the seating at banquets could, in some cases, alter political outcomes with a single gesture.
Servants, freedmen, physicians, and even family members often acted as go-betweens in these murders, either out of loyalty, fear, or calculation.
In Roman law, the penalties for poisoners were severe, yet prosecutions tended to focus mainly on slaves, lower-class women, or political scapegoats.
Those with enough influence often managed to evade punishment with help from the very people who benefitted from the deaths.
The accusations against Livia, the suspicious death of Germanicus, the banquet murder of Britannicus, and the failed poisoning of Domitian each appeared to expose a political culture where killing quietly often brought more success than open confrontation.
Ancient authors such as Pliny the Elder and Galen, who discussed toxic substances and antidotes in detail, noted that some of the same substances used to heal could also be adapted to kill.
In Rome, the person pouring your drink often proved more dangerous than the general in the field or the senator with a grudge.