Lisa Gherardini came from the ancient republican aristocracy of Florence of the 10th and 11th centuries. At the age of 15 she married a silk merchant, Francesco del Giocondo. Her portrait was commissioned after the birth of a son in 1503. To bring the figure’s movement and subtle smile of ‘Mona Lisa’ to life, Leonardo perfected the ‘sfumato’ (blurring) technique as far as possible, which consists of superimposing several layers of oil with little pigment to blur the contours. Leonardo da Vinci died in 1519, leaving the major work of his life unfinished.