Giuliano de' Medici
Although the sitter has traditionally been identified as Lisa del Giocondo, a lack of definitive evidence has long fueled alternative theories. During the last years of his life, Leonardo spoke of a portrait "of a certain Florentine lady done from life at the request of the magnificent Giuliano de' Medici." No evidence has been found that indicates a link between Lisa del Giocondo and Giuliano de' Medici, but then the comment could instead refer to one of the two other portraits of women executed by Leonardo.