Entitled "The Smile of Caterina, the mother of Leonardo," the book was inspired by a discovery that Vecce -- a professor at the University of Naples and an expert on the Old Master -- made at the State Archives in Florence in 2019 when working on the 500-year anniversary celebration of the great polymath's death.

There, he stumbled across a previously unknown document he says is dated the fall fo 1452 and signed by the man known to be the master's father, which, he says, frees a slave called Caterina from her mistress, Monna Ginevra. The date, which was a few months after Leonardo was born, and fact that Leonardo's father signed it struck Vacce as proof that this woman was Leonardo's mother.

Two years earlier, according to the same document, Ginevra had hired Caterina out as a wet nurse to a Florentine knight.

"I discovered the document about a slave named Caterina five years ago and it became an obsession for me," Vecce, professor of Italian literature at the University of Naples "L'Orientale," told CNN. "I then searched and found the supporting documents. In the end, I was able to find evidence for the most probabable hypotheses. We can't say it is certain, we don't look for the absolute truth, we look for the highest degree of truth, and this is the most obvious hypothesis."

The document describes the freed slave as having been born in the Caucsus area of central Asia and trafficked to Italy.

Vecce planned to continue his research in Moscow, where he felt sure he could find even more documentation about the slave trade in Italy and Caterina's life. But the Covid-19 pandemic put a halt to his travel plans, and instead, he said, he became "obsessed" with the story.

"The more I went forward, the more the story made sense. The story of a slave who was kidnapped at 13 and liberated at 25, the year after Leonardo was born. What should have been the most beautiful years of her life were spent as a slave," he said.

"A woman who lost her freedom"

Leonardo was born on April 15, 1452, in Anchiano, a hamlet near the Tuscan town of Vinci, about 25 miles west of Florence. His full birth name was Leonardo di ser Piero da Vinci, which means "Leonardo, son of Piero, from Vinci."

It had been thought that his mother was a local peasant named Caterina and his father a wealthy notary, according to official biographies of his life that were published at the 500-year-anniversary of his death in 2019.

Leonardo was born out of wedlock, and both parents married other people after his birth, but he spent his childhood on his father's estate, where he was educated and treated like a legitimate son.

There had been some suggestion within academic circles that Caterina had in fact been a slave, but there had never been any documentary evidence to support this theory -- until now. Vecce said the slave trade in Italy is rarely talked about, which may have led to the delay in this discovery.

"Here in Europe we know almost nothing about slavery in the Mediterranean. It was born in the Mediterranean at an extraordinary time, during the Renaissance," he said.

Vecce said he wrote his book about Caterina as a historical novel because so little is known about her whole life that he could not write an academic account.

"I could only fill 20 pages if (I wrote) an academic book, so I wrote a historical novel. I was drawn to this form of writing. I felt liberated to recount the story this way," he said.

Theory divides experts

Paolo Galluzzi, a historian of Leonardo's scientific work and member of the Lincei science academy in Rome, told CNN that Vecce's theory is "extremely plausible."

"It's based on documents and it isn't just fantasy," he said.

Though written as a novel, the story is inspired by "scholarly research," said Galluzzi, and is "by far the most convincing version up to now" of Caterina's back story.

"We have not the DNA of Leonardo or his mother or father, which would obviously provide the only scientific evidence," he said. "We rely on documents, and the documents that he (Vecce) has relied on are pretty convincing."

Not everyone agrees, however.

Martin Kemp, a leading Leonardo scholar and emeritus professor of art history at the University of Oxford, expressed more caution about Vecce's theory.

In a statement emailed to CNN, he described Vecce as a "fine scholar," but added: "It is a surprise that he has published his documents in the context of a 'fictionalised' account."

He said: "There have been a number of claims that Leonardo's mother was a slave. This fits the need to find something exceptional and exotic in Leonardo's background, and a link to slavery fits with current concerns."

Kemp explained that Caterina was a common name for slaves who had converted to Christianity. He pointed out that Francesco del Giocondo, the man believed to have commissioned the Mona Lisa as a portrait of his wife, traded slaves and, according to historical records, traded two "Caterinas" in one year.

Kemp, who in 2017 published "Mona Lisa: The People and the Painting" with co-author Giuseppe Pallanti, presented an alternative view of Caterina.

"I still favour a 'rural mother' -- Caterina di Meo -- a more or less destitute orphan in Vinci, but this is not as big a story if he had a 'slave mother,"" he said in his statement.

Whatever the truth about her identity, Vecce believes Leonardo's life work reflects his rapport with his mother.

He said Leonardo's depictions of the Madonna figure have always been based on a real woman, not religious iconography, and he believes Caterina's influence inspired his great success.

"The idea of the mother remained in his heart all his life. Caterina was the only woman in his life all his life, and he loved the smile of Caterina," he said.

The-CNN-Wire

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