A "'Golden Age' for Bastards,'" as academics have put it, was the time of Leonardo's illegitimate birth.

Leonardo was the illegitimate child of Caterina, a peasant, and Messer Piero Fruosino da Vinci, a successful and influential local lawyer. The parents of Leonardo da Vinci never wed. Before moving into his father's house, who had wed another lady, the young da Vinci lived with his mother until he was five years old. The artist kept diaries throughout his adult life, which reveal that he had a rather distant connection with his mother and only sometimes wrote to her. His texts imply a stronger relationship with his father, whose passing da Vinci mourned terribly.

Leonardo "had the good luck to be born out of wedlock," according to Isaacson, who makes this claim at the opening of his book. "He would have been sent to one of the classical schools in Florence for the aspiring upper-middle classes and rising middle classes, or a university, and he would have been stuffed full of the medieval scholastic learning of the time," Isaacson said on the podcast Recode/Decode. If he had been a legitimate son, he would have been expected to follow in his father's line of work and become a notary. Instead, Leonardo was formally untrained, but he was still able to pursue his interests, learn via experimenting, and pursue any kind of the arts, including poetry, sketching, etc.

Isaacson also points out that at the time, having an illegitimate child did not carry the same shame as it had in earlier times. Ten godparents attended Leonardo's baptism, which was a big occasion. He spent parts of his boyhood living with both his parents and his grandparents, and finally, his father assisted him in obtaining apprenticeships in Florence. There were many illegitimate offspring who rose to prominence in society, including members of reigning families like the Medicis and Borgias. It makes sense why bastards enjoy a "golden age" now.