Now new research claims to have an answer.
The research was unveiled at a news conference in Florence by Carlo Vecce, a scholar of Leonardo’s life and work, whose evidence will add new fuel to the fierce historical debate.
'I couldn't believe my eyes'
For centuries, as millions across the world admired his art and experts pored over his groundbreaking work in science, engineering and beyond, the exact identity of Leonardo’s mother has been the subject of intense scrutiny and speculation.
Some details were broadly agreed upon: Her name was Caterina and Leonardo was born in 1452 as the illegitimate product of her relationship with his father, a young Florentine notary named Ser Piero da Vinci.
Beyond that, theories abound.
Some scholars suggested Leonardo's mother was a peasant, others an orphan and some a slave hailing from the Middle East or North Africa. Now Vecce, one of the small group of Leonardo experts, says the evidence shows she was a Circassian slave torn from the North Caucasus region that today is part of southern Russia, near the coast of the Black Sea.
The “smoking gun” among the previously unknown documents Vecce claims to have found in the State Archives in Florence is an act of liberation of a slave called Caterina by her mistress, Monna Ginevra, who was the wife of a “Florentine adventurer” who owned slaves from the Black Sea region.
The document was written by Ser Piero da Vinci, Leonardo’s father, and dated November 1452, when Leonardo would have been 6 months old.
“When I saw that document I couldn’t believe my eyes,” Vecce told NBC News. “I never gave much credit to the theory that she was a slave from abroad. So, I spent months trying to prove that the Caterina in that notary act was not Leonardo’s mother, but in the end all the documents I found went into that direction, and I surrendered to the evidence.”
“At the time many slaves were named Caterina, but this was the only liberation act of a slave named Caterina Ser Piero wrote in all his long career,” Vecce said. “Moreover, the document is full of small mistakes and oversights, a sign that perhaps he was nervous when he drafted it, because getting someone else’s slave pregnant was a crime.”
The findings are the basis of a new historical novel by Vecce called “Il Sorriso di Caterina” (Caterina’s smile). According to Giunti, the book’s publisher, slavery from the Black Sea in the 15th century was a lucrative business for merchants from the powerful maritime republics of Venice and Genoa.
“In Florence the market demanded young women above all, destined for use as servants, caregivers, as well as concubines — sexual slaves who, if impregnated, continued to be useful even after giving birth, providing their milk to the master’s children,” it said in a news release.
If Leonardo’s heritage was just half Italian, as the research suggests, it would add a new layer to his rich legacy.
The Circassians are a mainly Muslim ethnic group who lived in the north of the Caucasus until the 19th century, when more than 1 million people were forced to flee their homeland after czarist Russia invaded the area.
Circassians now live in almost 40 different countries around the world, including Turkey, Israel, Syria, Jordan and the United States.
“Of one thing we can be sure,” according to the news release accompanying Tuesday’s research about Leonardo’s mysterious mother. “She is the one who passed on to him a respect and veneration for life and nature, and an inexhaustible desire for freedom.”
Until today, one of the most respected theories about Leonardo's mother came from Martin Kemp, another Leonardo expert and a former professor of the history of art at the University of Oxford in England.
In a 2017 book, Kemp concluded that Leonardo's mother was Caterina di Meo Lippi, an orphan who lived in a farmhouse about a mile from Vinci, the Tuscan village from which Leonardo was born and derived his name.
From documents he found in the archive of Vinci, Kemp concluded that Caterina and her infant brother moved to her grandmother’s house near Vinci after their parents died. Soon after, according to his theory, the former orphan became pregnant by the 25-year-old Ser Piero da Vinci during one of his visits to his hometown in July 1451.
“Carlo Vecce is a fine scholar. His ‘fictionalized’ account needs the sensation of a slave mother,” Kemp said in an interview Tuesday. “I still favor our ‘rural’ mother, who is a better fit, not least as the future wife of a local ‘farmer,’” he said.
“But an unremarkable story does not match the popular need for a sensational story in tune with the current obsession with slavery.”
Still, at the end of the day, Kemp warned, “none of the stories are demonstrably proven.”