© Rossella LorenziThe marble relief. A self portrait by Michelangelo?

A unique marble relief might be the first known self-portrait of Michelangelo, Italian art historians have announced this week.

Belonging to a private collection, the sculpture is a white marble tondo, or circle, about 14 inches in diameter. It depicts a bearded head in three-quarter profile.

"It's a very high-quality sculpture, carved with precision and delicacy. It certainly deserves much attention," Alessandro Vezzosi, director of the Museo Ideale in the Tuscan town of Vinci, told Discovery News.

The carving was identified as a possible work by Michelangelo back in 1999 by the late James Beck, professor of art history at Columbia University.

In his monograph The Three Worlds of Michelangelo, Beck called the artwork a "possible Michelangelo self portrait" and dated it to about 1545.

At that time, 70-year-old Michelangelo Buonarroti (1475-1564) had already completed masterpieces such as the David, the Pieta in the Basilica of St. Peter, the Medici chapels in Florence and the Last Judgement in the Sistine Chapel.

According to Beck, there was no doubt that the carved face of the old bearded man belonged to Michelangelo.

"It is the only portrait of Michelangelo in marble and in relief that I am aware of from his lifetime," Beck told Discovery News in an interview prior to his death in 2007.

Since Beck's attribution, interest in the tondo increased, and in 2005 the owners, a noble Tuscan family, accepted to briefly exhibit it at the Museo Ideale.

Six years later, the sculpture went on a temporary display (until the end of the month) at a museum in Caprese, Michelangelo's birthplace near Arezzo.

Following further research, another leading art historian, Claudio Strinati, general director of the Italian Ministry of Culture, backed up Beck's attribution.

"I find his hypothesis plausible. It is a portrait of Michelangelo or even a self portrait," Strinati said.

Indeed, the sculpture is consistent with known portraits of the Renaissance master, such as paintings by Giuliano Bugiardini and Jacopino del Conte, kept at the Casa Buonarroti museum in Florence, and bronzes by Daniele da Volterra, on display at the Ashmolean Museum in Oxford, England.

"My idea is that the portrait was conceived by Michelangelo when he worked on the tomb of Pope Julius II," Strinati said.

In 1505, Julius II (1443 - 1513) commissioned Michelangelo to execute his tomb. A work of massive proportions, it was expected to feature the greatest statuary the world had ever seen.

Intended to display forty life-size statues on a three-level structure, the tomb was never finished as the pope decided to suspend the work, instead assigning Michelangelo the job of painting the ceiling of the Sistine Chapel.

Nevertheless, Michelangelo worked on the tomb project intermittently for 40 years, between 1505 and 1545, well after the death of the pope who was entombed in St. Peter's Basilica in 1513.

Progressively downscaled, the project, which caused the artist much anguish, was finally set up in San Pietro in Vincoli in Rome in the form of a wall tomb.

It incorporated some of Michelangelo's sculpture, including the imposing figure of Moses.

According to Strinati, it is possible that the carved tondo was created as one of the sculptures which would have adorned the tomb.

Analysis carried by Corrado Gratziu and Alessandra Moscato at Pisa University, revealed that the marble used for the tondo came from Carrara in north-west Tuscany, more precisely from the Polvaccio quarry.

"Indeed, it is the same marble used for Julius II's tomb," Strinati said.

Gratziu and Moscato also found that the tondo had been left open to the elements for more than a century, and cleaned with acid. This would explain its smooth surface, which is not characteristic of Michelangelo's mature works (he was famous for giving an 'unfinished' look to his sculptures).

Although there is no provenance for the tondo, a 18th-century document found by Vezzosi records that Michelangelo donated a marble self-portrait to a family from Pisa.

"A very evocative hypothesis is that Michelangelo conceived the sculpture as a self-portrait to be positioned within Julius II's tomb. In this view, Michelangelo would have seen himself as an alter ego of Julius," Strinati said.

Although Michelangelo left no documented self-portraits, art historians have speculated that he painted his own image in the flayed skin of St. Bartholomew in the Last Judgement, and in the head of Nicodemus in the Florentine Pieta.

"We are talking of visual tricks that should encourage researchers to look for hidden self portraits in Michelangelo's works. The marble tondo could be one of them," Strinati said.