Portrait of Bianca Sforza

Leonardo da Vinci’s Lost Masterpiece

In 2010, a discovery shook the art world. A portrait of a young woman, purchased at a small auction in Switzerland for a modest sum, was identified by some experts as a previously unknown work by Leonardo da Vinci. The painting, known as La Bella Principessa, depicts Bianca Sforza, the illegitimate daughter of Ludovico Sforza, Duke of Milan. If authentic, it would not only expand da Vinci’s already extraordinary oeuvre, but also change our understanding of his work during the late 15th century.

The portrait’s journey into the limelight began when Canadian art collector Peter Silverman acquired it. At first glance, the delicate image seemed like a typical Renaissance portrait. However, certain details -- the subtle shading of the sitter’s face, the exquisite treatment of her hair, and the ethereal quality of the gaze -- suggested a hand far more skilled than the German artist to whom it had previously been attributed. Suspecting something greater, Silverman enlisted the help of leading da Vinci expert Martin Kemp.

Kemp, emeritus professor of art history at Oxford University, had spent decades studying Leonardo’s techniques. Upon examining the portrait, he was struck by several features. The sitter’s hairstyle and costume matched Milanese fashion of the 1490s, and the fine lines of the drawing displayed Leonardo’s characteristic sfumato technique -- the subtle blending of tones without abrupt edges. Moreover, the use of vellum -- a material made from calfskin -- was consistent with Leonardo’s known experiments during his Milanese period.

To bolster the claim of authenticity, scientific tests were conducted. Multispectral imaging revealed a series of faint fingerprint marks on the surface of the portrait. These prints, made in the paint layer before it dried, were compared with known fingerprints from Leonardo’s notebooks. Astonishingly, there appeared to be a partial match, suggesting that Leonardo himself might have handled the work. Further analysis of the pigments confirmed that they were consistent with materials available in the late 15th century.

Nevertheless, the attribution remains controversial. Critics argue that the portrait lacks the dynamism and innovation typical of Leonardo’s other works. Carmen Bambach, curator at the Metropolitan Museum of Art, is among those who remain unconvinced. She suggests that, while the portrait is of high quality, it could have been created by one of Leonardo’s pupils or a talented contemporary imitator. Such doubts are not uncommon in the world of Old Master attributions, where connoisseurship and scientific evidence often clash.

Adding to the intrigue is the identity of the sitter. Historical records indicate that Bianca Sforza was married at a young age to Galeazzo Sanseverino, a prominent Milanese courtier. Tragically, she died shortly thereafter at the age of 14, possibly from childbirth complications. The portrait’s subtle melancholy, combined with the youthful features of the sitter, supports the theory that it may have been commissioned to commemorate her short life.

The debate surrounding La Bella Principessa reflects broader challenges in art authentication. As technology advances, tools such as carbon dating, digital microscopy, and chemical analysis provide new insights. Yet they rarely offer conclusive answers. In the case of this portrait, scientific findings, historical context, and stylistic analysis each tell part of the story, but none can definitively declare Leonardo’s authorship.

For now, La Bella Principessa remains both a tantalising possibility and a symbol of art history’s enduring mysteries. Whether or not it is confirmed as a work by Leonardo, the portrait has captured the imagination of scholars and the public alike. As Martin Kemp once remarked, "Even if we can never be 100 percent certain, the dialogue between art and science has brought us closer than ever before to understanding this beautiful, enigmatic figure."