In the fifteenth book of his Annals, the Roman historian Tacitus introduces a ‘certain Epicharis.’ This qualifying ‘certain’ is heavily loaded: Epicharis is a woman and a former slave of unknown (or at least unstated) parentage and dubious, likely foreign origin, so that Tacitus should deign to mention her requires, it seems, some qualification. ‘Certain’ also writes a sneer into the text: this ‘charming’ woman (as her Greek name suggests) is said by another source to have been the mistress of Annaeus Mela (father of the poet Lucan and brother of the multi-hyphenate Seneca) and a prostitute. Others have suggested that she might, in fact, have been an actress. Tacitus does not mention any of this and at her first introduction simply points out that she was a freed slave with no previous interest in honourable causes.

This observation is significant because it is at this moment that Epicharis launches herself into the Pisonian conspiracy, the plot of 65 CE to kill the emperor Nero and replace him with the aristocratic celebrity senator Gaius Calpurnius Piso. The conspiracy failed catastrophically, ending in a blue-blood bath of suicides at Nero’s command and the shameful wholesale dobbing-in of family and friends as co-conspirators. And yet, Epicharis emerges in Tacitus’ account as a singular example of honour, determination and resistance.

Although the conspiracy centred around Piso, he was neither its instigator nor its leader; in fact, who played these parts is not at all clear. In any case, Nero was hated and Piso was popular, and the scheme drew wide support from across an unusually broad cross-section of society, involving both men and women. Its key figures, however, were all male members of Rome’s elite, many of whom were part of the imperial court: some were driven by the belief that the cruel and dissolute Nero was laying waste to the Roman state, but perhaps rather more of them were compelled by hurt feelings and personal rancour than by ideological motivations.

Among those, however, who sought to depose Nero as a means to rescue the state, Tacitus implies that Epicharis should be counted with them. None of our sources can say quite how she came to be involved in the plot but, in the know and frustrated at the dithering of the conspirators, Epicharis took action. She sought to enlist Volusius Proculus, a captain of the naval fleet at Misenum and agent in the murder of Nero’s mother, Agrippina, who felt himself insufficiently recompensed for so momentous a crime. An alliance with this henchman was hardly to Epicharis’ credit, and Tacitus’ account looks askance at the exchange with the subtlest of nods to the sexual history – made explicit in other sources – in the reference to their ‘friendship’ – perhaps of long standing, perhaps a more recent acquaintance. The connection, though, had strategic potential (Nero enjoyed frequent jaunts along the coast near Misenum), so Epicharis fed the fire of Proculus’ complaints by listing Nero’s crimes and, when he boasted of his desire for vengeance, she hinted that measures were in place by which the emperor’s punishment could be secured. Proculus promptly betrayed Epicharis, though his account was worthless as she had been careful to name no names and to ensure there were no witnesses to their exchange.

Nonetheless, Epicharis was detained by Nero, whose paranoia was in this instance justified, and when the plot unravelled thanks to a fatal betrayal from another quarter, she was tortured. Epicharis was not the first of the conspirators to be subjected to this treatment. Antonius Natalis, close confidante of Piso, was hauled in and gave up the names of his fellow-plotters at the mere sight of the rack. Though other men resisted a little longer, the names they gave were juicier still as if in apology for their delay. Lucan denounced his own mother. Epicharis refused to name a single conspirator.

When Nero remembered that Epicharis had been detained, his decision to subject her to torture was made, Tacitus tells us, in the confidence that her ‘woman’s body’ would not be able to withstand it. So the emperor’s henchmen set to work tearing her body apart with whips and flames; methods of torture made all the more furious by their fear of being defied by a woman. But she would not break her silence and, having survived a full day of the most violent torment, chose suicide by hanging as her means of escape. Her death is thus distinctly tragic and distinctly feminine: suicide by hanging is the fate of many great women of Greek tragedy – think of Jocasta, Phaedra, Antigone. But Epicharis’ suicide is doubly gendered because she fashioned her noose from her bra. With her limbs broken, unable to stand, Epicharis was carried back into the torture chamber on the second day in a chair; seeing an opportunity, she removed her breast band and formed it into a noose over the canopy of the chair, using the weight of her broken body to hang herself. This high-low blend of tragic method and comic means, rather than rendering the scene of Epicharis’ suicide absurd, is testament to her character and determination – a Stoic death that is a true reflection of the life it drew to a close.

Where Epicharis resisted torture with noble fortitude, the inglorious posh boys of the conspiracy threw up their hands and turned in their comrades. These men were the flower of Rome’s aristocracy, traditional models of the Roman masculine virtues of honour and constancy, and exemplary protagonists of moralising tales of right and wrong. They failed to live up to expectations. Epicharis’ resistance to torture is the most remarkable feature of her story, noted by all the few ancient sources in which she appears. But in Tacitus’ account, it is explicitly identified as a damning mark of the character of the age that exemplary conduct comes not from these elite Roman men but from Epicharis – a former slave, a foreigner, and a woman.

Tacitus’ Epicharis does not transcend her class or her gender; rather, they are the tools of the historian’s condemnation of those he feels should know better. Job done, she disappears from the narrative. But not before Tacitus has indulged in describing the abuses of her body in torturous detail; a treatment not bestowed on the male conspirators but lavished on Epicharis to create a spectacle of violence against the female body that is thus tarnished with the smear of titillation. This mingling of sex and violence is present, too, in our other ancient sources, and lingers on in places in Epicharis’ afterlife. In Daniel Casper von Lohenstein’s 1666 play, Epicharis, for example, the heroine’s torture is seen in graphic detail on stage. And in the best-selling French novel of thirty years earlier, Ariane, by Jean Desmarets de Sain-Sorlin, Epicharis escapes torture but struggles to evade the clutches of various would-be paramours: she is, it seems, too gorgeous for her own good. Proculus, for instance, betrays her not for political pay-off but because she won’t go out with him.

Desmaret’s Epicharis reads like a piece of fan fiction that fleshes out the potential of Tacitus’ historical figure: she is a swashbuckling adventurer who, in and out of a man’s disguise, makes not one but two prison-breaks, voyages across the sea, and is the key agent of the Pisonian conspiracy as a daring and devoted opponent of tyranny determined to avenge Nero’s persecution of her friends. Most of all, she is clever; a quality implicit in Tacitus’ historical account and for which Epicharis was praised by Machiavelli in his early sixteenth-century Discourses, where she appears as an example of the wisdom of plausible deniability, which left Proculus without corroboration when he turned snitch.

In her more recent afterlife, Epicharis has been celebrated as a part of feminist history. In Judy Chicago’s 1979 installation artwork The Dinner Party, Epicharis is one of the 999 mythical and historical women named on the ‘Heritage Floor’ that supports the three-sided table at which the thirty-nine place-settings of the female guests are laid. The women whose names are inscribed in gold lustre on the floor were selected for their contribution to society; for their attempts to improve the lives of women; as examples of key aspects of women’s history or as pioneers of a more equal society for all. They form a literal and metaphorical foundation for those with a place at the table. By naming Epicharis, Chicago marks her place in the history of women. The conspiracy may have failed but, as an example of female integrity and defiance, Epicharis endures.

Tacitus is no feminist, nor is he a class crusader, promoting the enslaved peoples of Rome. Epicharis’ brief appearance in the Annals is, to an extent, a means to an end: she offers a way for Tacitus to throw scorn on the ignoble behaviour of that class of men whose good actions ought, by Roman standards, to be the proper stuff of history. But for all this, the facts remain, and Tacitus offers us the fullest historical account of an undeniably remarkable woman, who fought the good fight against tyranny.