Rembrandt Van Rijn, Self-portrait, wearing a ruff and black hat. ( 1632). Courtesy Sotheby's.

One of the few self-portraits by Rembrandt van Rijn in private hands is hitting the auction block next month at Sotheby’s. And it comes with a juicy backstory.

The 1632 painting—created when Rembrandt was just 26 years old, the same year he made the famous The Anatomy Lesson of Dr. Nicolaes Tulp—is estimated to fetch between £12 million to £16 million ($15 million to $20 million). It will be offered on July 28 in a new cross-category auction in London, Sotheby’s first major evening sale in the city since lockdown began.

The painting, which depicts the artist in a stately ruffled collar and black hat, may have been designed to serve as a sort of “business card.” But another intriguing idea is that he created it to impress the relatives of his future wife, Saskia van Uylenburgh, a muse who would go on to appear in several of the artist’s well-known works. Some scholars believe that Rembrandt’s clothes, which suggest he is of similar status to his clientele, were intended to signal prosperity to van Uylenburgh’s bourgeois family. Notably, the canvas was painted at a small enough scale to send across the country to the town she lived in at the time.

When Rembrandt completed the painting, he was in the midst of establishing himself as a prodigal painter in Amsterdam. Sotheby’s co-chairman of Old Master paintings George Gordon says it is clear that the small composition was made quickly because the signature was added to the canvas when the paint was still wet. (A similar rendering of his signature, which Rembrandt only used for a brief period of time, is visible in The Anatomy Lesson of Dr. Nicolaes Tulp.)

“Rembrandt’s face is instantly recognizable to us at every stage of his adulthood—far more so than any other painter,” Gordon said. “In each self-portrait he reveals as much of himself as he chooses to, but always in his unique fluency in the handling of paint.”

The work has a fascinating market history. It last appeared at auction in 1970, when it was purchased from an anonymous collection by Paris collector J.O. Legenhoek for just £650 at a time when its authenticity was not yet certain. This time around, it is being sold by a collector who bought it in 2005 from Dutch dealer Noortman Master Paintings.

The last self-portrait by Rembrandt to surface at auction was sold in 2003, when Self-portrait with shaded eyes (1634) fetched €6.9 million ($11.3 million) at Sotheby’s London, according to the Artnet Price Database.