The mystery behind one of the most controversial paintings in art history may have just been solved. According to a new book, the model who posed for Gustave Courbet’s L’Origine du Monde (The Origin of the World) in 1866 was a ballet dancer named Constance Queniaux.

The painting, which depicts a close-up view of the genitals and abdomen of a naked woman, shocked Parisian bourgeois society when it was first unveiled. And it continues to shock today, with social media networks like Facebook routinely censoring the artwork. 

Courbet’s famous painting is largely credited with altering the course of art history by challenging long-held views on eroticism and what is acceptable to present as art. For more than 150 years, however, the identity of the sitter remained unknown.

But according to the Independent, a new book on the artist written by French historian Claude Schopp alleges that experts are “99 percent” certain the model was the Parisian dancer Queniaux. Art historians had previously thought that Irish model and Courbet’s lover Joanna Hiffernan sat for him for the painting. However, Hiffernan’s identity was frequently disputed because the painting’s dark pubic hair doesn’t match Hiffernan’s well-documented red hair.

Gustave Courbet’s L’Origine du Monde (The Origin of the World) (1886). Photo: THOMAS COEX/AFP/Getty Images.

The book details documentary evidence found in written correspondence between the son of writer Alexandre Dumas and novelist George Sand in which the pair discuss Courbet’s divisive painting.

Speaking to the French daily Liberation, Schopp said he found a clue when he read a confusing passage in one of the letters. It read: “One does not paint the most delicate and the most sonorous interview of Miss Queniault (sic) of the Opera.” When Schopp cross-referenced the passage with the original letter, he realized the answer had been hiding in plain sight. There had been a mistake in the transcription. The word “interview,” actually said “interior.”

Schopp contacted the head of the French National Library’s print department Sylvie Aubenas, who corroborated the hypothesis. “This testimony from the time leads me to believe with 99 percent certainty that Courbet’s model was Constance Queniaux,” she said, adding that contemporaneous descriptions of the singer’s “beautiful black eyebrows” correspond to the sitter’s dark pubic hair.

According to Schopp’s book, Ottoman diplomat Halil Şerif Pasha commissioned the painting from Courbet for his erotica collection. Queniaux, who had recently retired from the ballet at age 34, won the diplomat’s affections over the courtesan Marie-Anne Detourbay. The historian argues that the identity of the sitter was deliberately concealed when Queniaux ascended to Paris’s elite social circles.