Seraphita

Seraphita is a novel by Honoré de Balzac with themes of androgyny. It was published in the Revue de Paris in 1834.

The work plunges into the fantastic and the supernatural self (a genre that Balzac always approached with success).

In a castle in Norway near the fjord Stromfjord, Séraphitüs, a strange and melancholic being, conceals a terrible secret. Séraphitüs loves Minna, and she returns this love, believing Séraphitüs to be a man. But Séraphitüs is also loved by Wilfrid, who considers Séraphitüs to be a woman (Séraphîta).

In reality, Séraphitüs-Séraphîta is a perfect androgyne, born to parents who by the doctrines of Emanuel Swedenborg have transcended their humanity, and Séraphitüs-Séraphîta is the perfect example of humanity.

Ruggero Leoncavallo wrote a symphonic poem based on the story. - from Wikipedia