"Judith and Holofernes" originally was painted for Roman banker Ottavio Costa, one of Caravaggio's patrons. Costa kept it behind a curtain and would theatrically unveil it for visitors.

Caravaggio, “Judith Beheading Holofernes (c. 1598–1602), oil on canvas, 57 x 77 inches, held at Galleria Nazionale d’Arte Antica, Rome (image via Wikimedia Commons) ...

A painting believed by some experts to be Caravaggio's "Judith Beheading Holofernes" is pictured at the Marc Labarbe auction house on June 15, 2019, in Toulouse, France. (Eric Cabanis/AFP/Getty) ...

Opinions are divided as to the painting's authenticity, but the auction house is still predicting a monster sale. Caravaggio, Judith Beheading Holofernes (circa 1607). Courtesy of Cabinet Turquin.

David M. Stone, a professor of art history at the University of Delaware who is regarded as a Caravaggio expert, believes this “Judith” is real but understands where the doubters are coming from.

TOPSHOT - Workers carry a painting believed by some experts to be Caravaggio's "Judith Beheading Holofernes" for its public presentation at the Drouot auction house in Paris on June 14, 2019 ...

But Caravaggio's second Judith composition has been missing since 1617, the last time a reference to it was made.

Caravaggio, “Judith Beheading Holofernes” (1598–99) (Galleria Nazionale d’Arte Antica, Rome, via Wikimedia Commons) (click to enlarge) ...

France Caravaggio The Caravaggio' painting entitled "Judith Beheading Holofernes", is presented to the press, at the Drouot auction house in Paris, Friday, June 14, 2019.