Da Vinci is not his real name.
Yes, I’m still talking about the guy who painted the original Mona Lisa, good ol’Leo.
Leonardo was an illegitimate child. His father left after impregnating his mother, hence is true birth name was a singular Leonardo. (Source: What Was Leonardo's Name? Isaak, Shelly)
Leonardo did have a father but not a man he could lay claim to as his legal father due to his illegitimacy. His father ended up marrying 4 different times and had 7 children along the way, who of course, later fought over his estate.
Leonardo was able to at least claim ties to his biological father and avoid being branded a bastard child.
But his last name Da Vinci simply originates from his having been born near a town named Vinci. (Da Vinci = from Vinci)