Date of Birth: 1453.
When Giuliano was killed in the Pazzi Conspiracy, his son Giulio was considered legitimate due to a loophole in Canon law that allowed marriages to occur privately between two people, meaning that his parents could have agreed that they were actually married without telling anyone about it. Watch out Catholics - your mistresses have more power than you think.
Once legitimately a Medici, this child of a tradesman's daughter went on to become Pope Clement VII.
Son of a tradesman's daughter escapes poor past to become Pope, only to become a tradesman once more. Oh, the irony.