D'Eon

D'Éon was an 18th century French diplomat and spy. D'Éon was skilled with swords, (AUDIO: The Sword of the Chevalier) claiming to be one of the best duelists in France, although they rejected suggestions that they were the best. They were also familiar with Faction Paradox.

D'Éon's gender was a matter of contention among the aristocracy. Although some parties in England claimed that D'Éon was simply a man who occasionally masqueraded as a woman, D'Éon actively cultivated the mystery both of what their biological sex might be, and gave varying indications at different times about which pronouns they wished to be used in reference to them. To those not keen to simply chalk them up to being either a man or a woman, D'Éon usually went by the gender-neutral title of "Sieur D'Éon," instead of the gendered "Chevalier" or "Madame".

D'Éon was skilled with swords, claiming to be one of the best duelists in France, although they rejected suggestions that they were the best. They were also familiar with Faction Paradox. (AUDIO: Sabbath Dei)

History
D'Éon was born and raised in France as a man. (AUDIO: The Sword of the Chevalier)

D'Éon studied under the Count Saint-Germain but quit when the Count began claiming to be over a thousand years old.

D'Éon began acting as a spy for France, (AUDIO: Sabbath Dei) under Louis XV. (AUDIO: The Sword of the Chevalier) They soon became notorious as a spy, and thus decided not to bother to hide their occupation, instead cultivating a larger-than-life persona as a living mystery, which drove diplomats to invite D'Éon to their galas and parties despite the potential security leak. In the course of their spycraft, D'Éon, while presenting as female, spent months among the Russian court.

While working as a spy in England, D'Éon got themselves in trouble with a French court and ended up exiled in England, becoming a reknowned figure in high society. (AUDIO: The Sword of the Chevalier)

In 1762, the Sieur d'Éon attended the Hellfire Club's ball at Medmenham Abbey. There, d'Éon investigated the site of Mary Culver's ritual and was followed by Sabbath. They met Cousin Justine and witnessed her timeship rise from the ground. Later, d'Éon met Mary Culver and was enlisted, along with Cousins Justine and Eliza, to stop Lolita's plot. (AUDIO: Sabbath Dei)

Justine was revulsed by the idea of a man masquerading as a woman or vice versa (despite herself carrying the Grandfather's shadow); likewise, d'Éon mistrusted Justine for being a self-appointed Messiah. However, d'Éon worked well with Eliza, and together with Lord Sandwich, they destroyed Lolita's army of 500 Peking Homunculi under Buckingham Palace. (AUDIO: In the Year of the Cat)

In 1791, D'Éon visited Slough where they had a fencing match with the Tenth Doctor. The Doctor and Rose Tyler travelled to London with them. They went with Rose to find Joxer and Hempel before she was captured to be a slave. They then fought Joxer's copies of the attendants so that the Doctor could get to the ship. On board, they suggested a fencing match against the slavers. (AUDIO: The Sword of the Chevalier)

Behind the scenes
The possibility that D'Éon might be an agent of the Great Houses is alluded to in The Book of the War, although they are not named, as it is stated that "Robert Scarratt suggested that agents with specifically transvestite or transexual orientations would present an initially ambiguous sexuality, and be more 'organically and symbolically' capable of dealing with the alter-time of the Houses' opponents".

Although this is expressed with a now-antiquated term, this would constitue confirmation that the Faction Paradox character is intended to be read as a transgender, genderfluid person. In the real world, the 's actual gender identity remains a point of scholarly debate; although it is certain that they would, by modern standards, at the very least have been "gender-non-conforming", the specific depiction of d'Éon in Sabbath Dei as genderfluid (asking at various times to be addressed with female or male pronouns and honorifics) is not unanimous, with some arguing that D'Éon was in actuality a transgender woman, while others maintain that they were merely a man taking advantage of a gender-ambiguous appearance for purposes of spycraft.