In 1517, Leonardo showed a visitor a portrait of Lisa del Giocondo ... a theme he had been exploring on and off for years – the Madonna and Child with Mary’s mother, Saint Anne.

"The infrared examination of the Isleworth Madonna [as Earlier Mona Lisa ... (who say they themselves are not sure if the portrait is a real Leonardo) began legal proceedings against the Mona ...

conveyed Leonardo's maxim that a portrait should reveal "motion of the mind." Kemp also needed proof that the portrait had been made during Leonardo's lifetime (1452-1519) and that its historical ...