Art conservators and curators at the Art Gallery of New South Wales in Australia have uncovered a mysterious underlying portrait in a 16th-century painting of Duke Cosimo de’ Medici. The painting, known as Cosimo I de’ Medici in armor (c. 1545), was created by the renowned Italian Mannerist painter, Angnolo di Cosimo, or Bronzino, and has at least 25 versions. The investigation, using X-ray fluorescence (XRF) microscopy, revealed that Bronzino had originally painted the Duke as a scholar wearing a hat and holding a book before he changed the image to depict him as a virile fighter.
The study was conducted by Simon Ives and Paula Dredge, painting conservators at the Art Gallery of New South Wales, along with Anne Gérard-Austin, the curator of international art. They worked with scientists from the Australian Nuclear Science and Technology Organisation, using a synchrotron particle accelerator and specialised Maia detector microscopy to scan the painting. The team used synchrotron elemental maps to understand the sequences of paint application, affirming the chronology and sequence of the Cosmo in armour series and confirming it as the primary three-quarter length archetype, a fully autographic painting by the master.
The XRF microscopy revealed that Bronzino had painted Cosimo de’ Medici as a scholar before later changing the painting to depict him as a fighter dressed in immaculate armour with brilliant crimson trimmings. The reasons for the shift in persona are unknown, but scholars suggest that the Duke may have wanted to present himself as a fighter rather than a thinker, although notably without a weapon, an omission that pays deference to Charles V, to whom he owed much of his political stability.
The underpainting is believed to be the basis for a later work, Portrait of a Young Man, now in the Nelson-Atkins Museum in Kansas City. The portrait had long been in private hands until the 1970s when it emerged from obscurity. Robert Simon, an art historian, published a paper in 1983 that proposed the primacy of the painting and later published an X-ray image of the painting.
The investigation has further solidified the credentials of the painting hanging in the Art Gallery of New South Wales as the prime autograph version of Cosimo I de’ Medici in armour. The painting has been replicated widely, and there has been longstanding debate about the chronology and which versions were painted by Bronzino himself.
The painting remains the only work by Bronzino in an Australian collection and was purchased by the Uffizi Gallery’s foundation in 1996 for $1.88. The investigation into the painting and the discovery of the underlying portrait has been a significant achievement for the team at the Art Gallery of New South Wales and has provided valuable insights into the work of one of the most renowned painters of the Renaissance period.
