Bianca Sforza attracted few stares when introduced to the art world on January 30, 1998. She was just a pretty face in a frame to the crowd at a Christie's auction in New York City. Nobody knew her name at the time, or the name of the artist who had made the portrait. The catalog listed the work—a colored chalk-and-ink drawing on vellum—as early 19th century and German, with borrowed Renaissance styling. A New York dealer, Kate Ganz, purchased the picture for $21,850.
The price hadn't budged almost ten years later when a Canadian collector, Peter Silverman, saw Bianca's profile in Ganz's gallery and promptly bought it. The drawing might actually date from the Renaissance, he thought. Ganz herself had mentioned Leonardo da Vinci, that magical name, as an influence on the artist. Silverman came to wonder, What if this is the work of the great Leonardo himself?
That someone could walk into a gallery and buy a drawing that turns out to be a previously unknown Leonardo masterpiece, worth perhaps $100 million, seems pure urban myth. Discovery of a Leonardo is truly rare. At the time of Silverman's purchase, it had been more than 75 years since the last authentication of one of the master's paintings. There was no record that the creator of the "Mona Lisa" ever made a major work on vellum, no known copies, no preparatory drawings. If this image was an authentic Leonardo, where had it been hiding for 500 years?