It is supposed, that Francesco di Bartolommeo di Zanobi del Giocondo, one of the noblest citizen of Florence, ordered from Leonardo a portrait of his third wife Lisa di Antonio Maria di Noldo Gherardini. Leonardo started to work at this painting in 1503. At this time Mona Lisa was twenty-four year old. He worked at the portrait for the next four years. When Leonardo left Florence in 1507 he did not sell the painting to the orderer but he kept it for himself. Several believe, that Leonardo did not hand over the painting, because he did not finish the work, other believe that Leonardo loved the painting to much.