In his enchantingly simple representation of the back of a painting, the Dutch painter Cornelis Gijsbrechts not only addressed the art of illusion, but also conveyed the suggestive power of looking behind a picture.
Sometimes the backs of old paintings are more revealing than the subject itself.
At least they show the researcher a way with their handwritten notes, inventory numbers, seals and labels.
This is the case with the panel, which arrived at Sotheby's in New York in the spring from restituted German-Jewish possessions and now, after an extensive search for traces, in January with a cautious estimate of three to five million dollars as a new discovery from the oeuvre of the Medicean court painter Agnolo del Bronzino will be auctioned.
The Mannerist portrait of a young man with a pen was believed to be the work of the Florentine artist Jacopino del Conte, a student of Andrea del Sarto, when it was delivered to the auction house in uncleaned condition.
It was known that the collector Ilse Hesselberger, granddaughter of the founder of the German sewing machine factory Joseph Wertheim in Frankfurt and wife of the Munich industrialist Frank Hesselberger, had acquired the panel in 1927 from the Munich art dealer Julius Böhler as a work by Francesco Salviati.
For 55,000 Reichsmarks to Hitler's Reich Chancellery
By expropriation or forced sale, it returned to the Munich art market by 1938 at the latest, three years before the 51-year-old Ilse Hesselberger was abducted to Kaunas in Lithuania in November during the first deportation of Jews from Munich and murdered there on arrival.
In January of the same year, the dealer Maria Gilhausen had sold the portrait to the Reich Chancellery for 55,000 Reichsmarks through the mediation of Hitler's interior decorator Gerdy Troost.
Inventory numbers record further stages of the panel, which has since been attributed to del Conte, from the inventory of the Linz Führer Museum to the depot in the Altaussee salt mine, where the Hitler regime stored its art treasures to protect them from bombing raids, to the Wiesbaden collection point for looted art.
From there, the painting passed from the office of the Hessian Prime Minister into the possession of the German Parliamentary Society, which last year gave it to the estate of Ilse Hesselberger's daughter, who escaped to New York in 1938.
The many inscriptions, numbers and labels not only enabled Sotheby's to trace the provenance back to the 17th century, but also to determine that the portrait, then owned by the English diplomat and essayist Sir William Temple, was listed as a work by Bronzino.
Temple, who employed the young writer Jonathan Swift as his secretary, may have been attracted to the portrait because, again as noted on the reverse, it was believed to be a portrait of the Renaissance philosopher Pico della Mirandola.
In the course of later sales, the connection to Bronzino was lost.
When the picture came into the possession of the art historian August Liebmann Mayer, who specialized in Spanish painting, after 1920, it was considered a work by Salviati.
The art historian Carlo Falciani, co-curator of the major Florentine Bronzino retrospective of 2010, was immediately convinced that the portrait was an early work by the artist.
He even speculates that it could be a self-portrait of the poetic painter, who, with the inkwell balanced precariously on a needle and the handwritten Latin quatrain over which the young man raises his pen as if he had just written it, points to the contest between the contemplative alludes to writing and active painting.