Did Leonardo create it?

The Flora Sculpture at the Bode Museum Underwent a New Dating Method

Leonardo da Vinci is today as much a media phenomenon as an artistic one, but public interest and curiosity about his figure have persisted for many decades, if not centuries. Since at least the 19th century, fascination with his works has grown rapidly, leading to a remarkable series of attributions—many of them disputed. In fact, art historians have often struggled to find solid evidence linking certain works to Leonardo, and in many cases, such proof has not been found.

The wax bust of Flora, measuring 67 x 44 x 37 cm, currently on display at the Bode Museum in Berlin, had been attributed to Leonardo mainly on stylistic grounds, due to similarities with the female figures painted by the artist. However, this attribution has been the subject of intense debate since the statue was acquired in the early 20th century.

Only recently, through new chemical analyses and absolute dating using the Carbon-14 method—carried out by experts from the French National Centre for Scientific Research (CNRS), in collaboration with the museum and Paris-Saclay University—has it been possible to find a conclusive answer.

By 1911, just two years after Wilhelm Bode, the then director general of the Royal Museums of Berlin, had purchased the sculpture, more than 730 articles had already been published in the international press—German, English, French, Italian, Austrian, and Danish—both supporting and refuting the attribution to Leonardo. This clearly demonstrates the enormous interest that Leonardo’s works have always generated and continue to provoke today.

A photo of the museum room in 1917 shows Flora on the back wall.

The main reason for doubt about the attribution to Leonardo was the material used to create the bust: wax—a very unusual medium for a Renaissance artwork. To date, no other wax sculptures from this period are known. However, Leonardo was famously a relentless experimenter.

Bode purchased the bust at a London auction for the very high price of 185,000 gold marks, attributing it to Leonardo based on the enigmatic smile, graceful posture, modeling of the flesh, and virtuosic treatment of the drapery. This, despite other scholars, such as Gustav Pauli (then director of the Hamburg Museum), having attributed the work to Richard Cockle Lucas (1800–1883), a 19th-century British sculptor known for producing many wax sculptures in ancient styles.

Confirmation that the bust had indeed been made by Lucas came in 1910 from his son, Albert Dürer Lucas, who swore he had helped his father create the piece around 1846 and even provided technical details.

Nonetheless, Bode remained steadfast in his belief that the sculpture was an original Renaissance work, dismissing the supposed confession as a conspiracy against him.

According to the museum’s website today:

“In 1909, the director of the Berlin museums, the renowned expert Wilhelm von Bode, purchased this wax bust of Flora, which he immediately attributed to Leonardo da Vinci or his circle. A few weeks later, an amateur English painter with the curious name Albrecht Dürer Lucas claimed that the work had been created by his father about sixty years earlier. This marked the beginning of one of the great controversies in art history—between those who supported the Leonardo attribution and those who considered the bust a forgery. A century later, the debate remains unresolved. The object is currently undergoing scientific analysis, from which we hope to gain new insights to answer the crucial question: is the Flora bust a work by Leonardo?”

As early as 1910, chemical analysis of the bust had revealed the presence of spermaceti—a substance found in liquid form in the head of living sperm whales and which solidifies into a whitish mass upon the animal’s death.

Although spermaceti wax was rare and expensive during the Renaissance, it was indeed known at the time, meaning its presence could not rule out a possible attribution to Leonardo. However, it was much more commonly used in the 19th century for candles and small sculptures—so much so that it contributed to a steep decline in sperm whale populations.

In Leonardo’s time, as today, the most commonly used wax in art was beeswax, which has been used since prehistoric times.

The arguments in favor of dating the Bode bust to Leonardo’s era were therefore mostly stylistic, since scientific analyses throughout the 20th century had proven inconclusive. One expert, after analyzing the bust’s surface, claimed that the cracks present indicated significant aging, making a Renaissance origin more plausible than one from just a few decades earlier.

From a stylistic point of view, experts also noted that the polychromy appeared to have been applied using Renaissance techniques and that Flora’s face closely resembled other female figures painted by Leonardo.

Still, stylistic evidence alone was not enough to convince everyone. More recent analyses were therefore carried out.

The turning point came when experts decided to adapt the Carbon-14 method to obtain new and definitive dating results. Several wax samples were taken—from both the surface and interior of the bust, as well as from the filling materials at the back. For comparative purposes, samples were also taken from two wax bas-reliefs by Richard Cockle Lucas, one dated 1848 and the other 1850.

But using the standard Carbon-14 method—typically applied to organic materials such as canvas and wood—was not sufficient. To accurately calibrate the 14C results from the wax samples, it was necessary to carefully identify the composition of the material.

This case was especially complex. As previously noted, the waxes from the Flora bust and one of the 19th-century Lucas bas-reliefs are composed primarily of spermaceti from sperm whales—large marine mammals. This spermaceti was then mixed with small amounts of beeswax and other organic compounds from terrestrial animals. Thus, the material was mostly marine in origin with some terrestrial elements.

The breakthrough was recognizing the need to account for the so-called Marine Reservoir Effect. Terrestrial animals derive their carbon from sources in equilibrium with the atmosphere, whereas marine animals like whales consume older carbon from ocean ecosystems. This discrepancy requires a correction in the dating process when mixed-source materials like this wax are involved.

Thanks to this refined approach, the final result showed that all the materials making up the Flora bust date with certainty to after 1700 CE, definitively ruling out the possibility that the sculpture was created during the Renaissance—and therefore excluding Leonardo da Vinci as its author.

This result is only partly surprising. The 1910 statement by Richard Cockle Lucas’s son had already dispelled much of the doubt, but the new study provides solid, scientific confirmation of that confession. Moreover, the research helped refine a new Carbon-14 dating methodology.