Leonardo da Vinci’s mother was a teenage slave girl who was trafficked to Italy across the Black Sea from the Caucasus, new research unveiled on Tuesday claimed.

Carlo Vecce, an Italian historian, discovered a document in archives in Florence which granted the teenager, whose name was Caterina, freedom from slavery.

The document suggests that she was from what was then known as Circassia on the north-eastern shores of the Black Sea, meaning that Leonardo da Vinci, one of the titans of the Renaissance and considered a quintessentially Italian figure, was only half-Italian.

Prof Vecce, from the University of Naples L’Orientale, believes she was kidnapped from Circassia, possibly by Tartars, and then shipped across the Black Sea to Constantinople and from there to Venice.

She was then acquired by a family in Florence for whom she worked as a wet nurse.                                               

Married off with a generous dowry

It was there that she was made pregnant by Leonardo’s father, Ser Piero da Vinci, in the summer of 1451.

Once the baby was born Caterina was swiftly married off, with a generous dowry, to a local smallholder with whom she went on to have five children.

The document which freed her from slavery is dated Nov 2, 1452 – seven months after Leonardo was born in the town of Vinci.

The certificate, written in Latin, refers to Caterina as being “a slave” who had originally been taken from “Circassia”.

The document, found in the State Archives of Florence, was signed by Piero da Vinci, Leonardo’s father, who was a prominent notary in the city.

“The notary who freed Caterina was the same person who loved her when she was still a slave and with whom he had this child,” Prof Vecce told a press conference in Florence.

He presented his findings in a new book, Il Sorriso di Caterina or Caterina's Smile.

“Leonardo was the son of a notary but he was only half-Italian, his mother a foreigner and a slave, a woman on the lowest rung of the ladder at the time,” he said.

Although the theory that Leonardo’s mother was a teenage slave girl has been around for a couple of decades, the connection with the Caucasus is new. And the discovery of the act of freedom lends the slave narrative more weight.