For more than 300 years, the sitter was believed to be a jaunty, mustachioed Russian aristocrat painted by a minor Dutch artist.
But following a hunch, and years of painstaking restoration work that saw the removal of the tall hat, mustache and gold earrings, a beautiful self-portrait of the Dutch master Rembrandt van Rijn at the age of 28 has been revealed. This long-lost work, entitled Self Portrait with Shaded Eyes and painted in 1634, is now due to be auctioned by Sotheby's in London and is expected to fetch between £4-million ($8.9-million Canadian) and £6-million. The July 10 sale is the first time in 30 years that a Rembrandt self-portrait has gone on the market, and the previous painting, sold in 1973, may not actually be a work of the artist.
The reworking by one of the artist's pupils in his Amsterdam studio has also raised new questions about Rembrandt's motives for producing such a large number of self-portraits -- 80 in total -- over his lifetime.
The traditional, romantic view -- that they were "the greatest single legacy of self-revelation in Western art," in the words of one awed historian -- may need some revision. For it appears that Rembrandt had shrewd commercial motives: He was famous enough that his portraits were in demand, and if a particular one was not purchased, he or a pupil in his studio would paint it over and sell it. That appears to be what happened in this case.
"We can't be sure, but it is a logical explanation of what happened," said George Gordon, an Old Master expert at Sotheby's. "At the time, it was fashionable to visit painters in their workshops. Rembrandt was the most famous painter of his time and he would have been visited frequently. A portrait of and by a famous artist was desirable."
When Rembrandt failed to sell it after two or three years, it is believed, he allowed an unnamed pupil to add the extra attire, transforming it into a study of a colourful Russian nobleman, which bore no resemblance to the young artist.
Portraits of aristocratic Russians were typical of the "tronies," or fantasy pictures, bought by the Dutch middle classes, as it satisfied their curiosity regarding exotica.
"People were excited by exotic figures in far-off lands," Gordon said. "Remember there was the great speculation in tulips, people collected sea shells and in general all things foreign and exotic. This painting fulfilled that."
The portrait remained untouched until the 20th century. In 1956, the removal of the over-paint began when the curious owner employed a restorer who took away the hat with a harsh solvent. Then, in the 1960s, the current owner's father arranged for the earrings, mustache and extensions of the hair to be removed, but the work was left incomplete and in a hybrid state.
In 1995, the owner, eager to solve the mystery of the sitter's identity once and for all, contacted the Rembrandt Research Project in Amsterdam for further investigation. In 2000, the final process of removing the remaining layers of pigment began with the help of Martin Bijl, former head of conservation at Rijkmuseum in the Dutch capital. Using a surgical scalpel and a magnifier, Bijl carefully powdered off layers of heavy paint one tiny stroke at a time, a process that took three years. It was a precarious method as the over-layers were lead paint.
X-rays and infrared could not penetrate the over-layers to reveal if there actually was original paint underneath.
So Bijl bore two tiny holes around the sitter's eye and there, under the rather clumsy over-paint lay Rembrandt's own, highly accomplished brushwork.
"If you aren't careful you could strip away the original paint. Martin Bijl wanted to reveal the brush strokes, and ridges," Gordon said.
The self-portraits by Rembrandt perhaps make him one of the most catalogued faces in the history of art.
The artist was obsessed with chronicling his youth, middle and old age, and left behind 40 etchings and drawings, and 40 paintings, of himself.
But why didn't Rembrandt simply paint another tronie instead of transforming an already finished work?
Gordon said the prosaic reason was that panels on which it was painted were made from Baltic oak, a high-quality and extremely expensive wood.
It would have been considered wasteful to use it for a work that would not be sold.
"We know that at the same time Rubens was not using Baltic oak panels for experimental paintings -- and Rubens was a rich man," he said.
There are three other known hidden self-portraits of the Old Master in existence.
Through the use of X-ray imaging and infrared technology, art restorers found that a painting in the Royal Collection in London owned by the Duke of Sutherland, one in Berlin and a third in the Louvre reveal the artist underneath.
But Gordon said it was extremely unlikely the over-paint would be taken off in those cases.
Certainly, if the current portrait came to the auction house in its original state, it would not have been altered.
"The view is the over-paint would be taken off only if someone in the past did it," he said.
You'd be interfering with history otherwise."