The Mona Lisa’s long-debated identity and creation date were clarified in 2005 when a German researcher uncovered a verified handwritten note in a book’s margin indicating that Leonardo da Vinci was painting a portrait of Lisa del Giocondo in 1503. In 2005, researchers at Heidelberg University revealed a handwritten 1503 marginal note that helped support both the identity of the Mona Lisa and the date Leonardo da Vinci began painting it. The annotation was found in a copy of Cicero’s letters written by Agostino Vespucci, a Florentine official and associate of Leonardo. In the note, Vespucci compared Leonardo to the ancient Greek painter Apelles and mentioned that he was working on “the head of Lisa del Giocondo,” strengthening the long-held view that the painting depicts Lisa Gherardini, wife of Francesco del Giocondo. Historians had long linked the work to her through later sources like Giorgio Vasari, but this contemporary 1503 reference provided rare firsthand evidence that the portrait was underway in Florence by October of that year.(Historic Vids)