Later historians described this engraving and, despite having never seen the painting, catalogued its existence.

It was bought by 19th-century French academic painter William-Adolphe Bouguereau and passed down through his family, according to the auction house.

The painting was authenticated by German art historian Nils Buttner, known for his research on the master of the Flemish Baroque, Osenat said.

Its provenance was certified through methods including X-ray imaging and pigment analysis, he added.

“It’s the very beginning of Baroque painting, depicting a crucified Christ, isolated, luminous and standing out vividly against a dark and threatening sky,” he said.

Although Rubens produced many works for the Church, the painting, measuring 105.5 by 72.5cm, was likely to have been created for a private collector.

-Agence France-Presse