Presenting himself as a nobleman, military veteran, and esteemed lawyer from Bordeaux, France, Pierre Henri Treyssac Vergy cultivated an image of affluence and prestige. However, contemporaries met his claims of high birth and professional accomplishments with skepticism. Vergy’s complete history remains unknown, complicated by financial difficulties and the use of multiple aliases. While he boasted connections to the French aristocracy, including relations to a former War Commissioner Monsieur Letourneur, evidence suggests a more humble origin. Likely born in Bordeaux in 1732, Vergy appears to have been a young adventurer with limited means, arriving in London as part of an ill-conceived scheme.

Vergy says he turned to writing after depleting his wife’s dowry and inheritance. In August 1763, he sought favor from the French Embassy in London but was rejected by Chevalier D’Eon de Beaumont, the embassy’s head and a secret agent for Louis XV, due to poor credentials and unfavorable reports. Their conflict intensified when the new Ambassador, Comte de Guerchy, arrived on October 17, 1763, and D’Eon, frustrated by his diminished influence, directed his anger toward Vergy.

Vergy and D’Eon’s public feud erupted in October 1763, resulting in a duel prevented by English authorities. Intimidated, Vergy recanted, but was later imprisoned due to subsequent legal actions and debt. While incarcerated, he reversed allegiances, attacking Ambassador Guerchy in a pamphlet before being transferred to Newgate Prison, where he would spend ten months. Released in 1764, Vergy sought reconciliation with D’Eon. Leveraging his literary connections, he accused a group, including Guerchy, of conspiring to remove D’Eon as an ambassador and offering a position to Vergy. When his fabricated schemes failed, he was offered a bribe to assassinate D’Eon, which he refused. Determined to expose the conspiracy, Vergy accused Guerchy of attempted murder in the papers. In early 1765, this accusation led to an indictment against the Ambassador despite his protests to the English government. The King of England intervened to prevent a trial, stopping the proceedings against the Ambassador and indicting Vergy for conspiracy by Mid-1765. However, this ultimately failed. The Comte de Guerchy was eventually recalled to France, where he died, bringing an end to the entire affair.

Contemporary accounts depict Vergy as a deceitful adventurer and social outsider during and after the controversy. Horace Walpole criticized both Vergy and D’Eon, calling Vergy’s conspiracy claims “clumsy” and “abominable.” The author found D’Eon’s threat to put Vergy’s soul “into the chamber-pot and make him drink it” amusing, and Walpole saw both this and D’Eon’s reaction to Vergy’s “wild book” as clear evidence of their unreliability and irrationality. Philip Dormer Stanhope, Earl of Chesterfield, remarked that Vergy’s actions caused “disagreeable difficulties.” He added that Vergy’s sworn deposition to a Grand Jury deliberately complicated matters, casting doubt on his trustworthiness. The Earl of Chesterfield cautioned his son, saying, “il y a de la merde au bout du bâton, quelque part” (“There’s shit at the end of the stick, somewhere”).

Between 1765 and 1769, he published only A Letter Against Reason (1767), a philosophical treatise addressed to Chevalier D’Eon. Vergy’s 1769 debut novel, Mistakes of the Heart, blended sentimentality with naturalism while aiming to appeal to English readers. Praised for style, it was criticized for explicitness. The Critical Review preferred the work's decency over its emotional intensity, while the Monthly Review scorned Vergy’s “egregious” misrepresentation of the English aristocracy. Vergy’s The Lovers (1769), a scandalous bestseller inspired by Lady Sarah Bunbury’s elopement, was widely read but criticized for explicit content and libel. His novel Henrietta, Countess Osenvor (1770) received mixed reviews. The Critical Review praised its characters and language, while the Monthly Review considered it “decent” but lacking in substance. Vergy’s Nature (1770) amplified the explicit content of Mistakes of the Heart and readers rejected it. Reviews like “The author... paints the havock which the passions make... but his writings are rather calculated to render that havock more extensive than to stop its progress” and “a licentious performance” suggest the level of outrage. The authentic memoirs of the Countess de Barre (1771) was dismissed by the press as “another heap of rubbish swept out of Mons. Vergy’s garret.” He was around 39 in 1771 and had only one year left in his career. By 1772, the phrase “in the manner of M. de Vergy’s worst performances” had become a byword for indecency and frivolity.

Pierre Henri Treyssac de Vergy’s literary career ended in 1772. He authored a total of 11 texts and passed away on October 1, 1774, at approximately 42 years old. In his will, he reaffirmed his earlier statements on the De Guerchy-D’Eon controversy. He died, known to his English readers as an adventurer, spy, scandalmonger, pamphleteer, and novelist of “infamous memoirs.”