Explore the Warsaw copy of the Sforziada about the Support for Leonardo attribution of this artwork.
In 2011, after the publication of the first edition of their book, Kemp and Pascal Cotte reported that there was evidence that the drawing had once been part of a copy in the National Library of Poland in Warsaw of the Sforziada.  This is a printed book with hand-illuminated additions containing a long propagandistic poem in praise of the father of Ludovico Sforza, who was Leonardo's patron, recounting the career. The Warsaw copy, printed on vellum with added illumination, was given to Galeazzo Sanseverino, a military commander under Ludovico Sforza, on his marriage to Bianca Sforza in 1496. Kemp and Cotte identified where two sheets were missing from this volume from which they believe the drawing was cut. Kemp and Cotte say that, although "the dimensions and precise locations of the holes in the portrait cannot be obtained with precision", the three holes on the left-hand side of the drawing can be aligned with three of the five stitch holes in the sheets in the book.According to Kemp and Cotte, the association with the Sforziada suggests that the drawing is a portrait of Bianca Sforza, who was the daughter of Ludovico Sforza and his mistress Bernardina de Corradis. At the time of the portrait, she was around thirteen years old. Leonardo painted three other portraits associated with the family or court of Ludovico Sforza.
The Polish scholar Bogdan Horodyski in 1954-1956 reached the conclusion that the Warsaw illumination refers to both the deceased dukes Galeazzo Maria and Gian Galeazzo and to the dynastic downfall after the usurpation of Ludovico il Moro.  The reproduction of the unpublished heraldic figure attributed to Antonio Grifo, illuminated in the incunabulum "Comedia" by Dante (Cremonese, Venice 1491), now at Casa di Dante in Rome, shows the original coat of arms and insignia of the family of Galeazzo Sanseverino, and the comparison with those illuminated by Birago is not corresponding. Developing this hypothesis, Carla Glori suggests that Caterina Sforza, the daughter of Galeazzo Maria and half-sister of Gian Galeazzo, was the owner of the Warsaw Sforziad and that she gave it to the family of her deceased half-brother between 1496 and 1499.  Horodyski's ideas have recently been revived by Katarzyna Krzyzagórska-Pisarek in her "La Bella Principessa. Arguments against the Attribution to Leonardo", Artibus et Historiae, XXXVI, 215, pp. 61– 89. Pisarek is a member of Artwatch UK, which has offered polemic denunciations of Kemp.
vellum Ludovico Sforza Warsaw Sforza National Library of Poland