The title of the painting, which is known in English as Mona Lisa, comes from a description by Renaissance art historian Giorgio Vasari, who wrote "Leonardo undertook to paint, for Francesco del Giocondo, the portrait of Mona Lisa, his wife."[16][17] Mona in Italian is a polite form of address originating as ma donna – similar to Ma'am, Madam, or my lady in English. This became madonna, and its contraction mona. The title of the painting, though traditionally spelled Mona (as used by Vasari),[16] is also commonly spelled in modern Italian as Monna Lisa (mona being a vulgarity in some Italian dialects), but this is rare in English