This image of St John the Baptist was the last painting that Leonardo produced, and it was in his possession when he died. It is one of only a few that we can be absolutely certain the master painted. Leonardo's version is strikingly different to other paintings of the Saint, who is normally portrayed as gaunt, and scraping a living in the desert on locusts and honey.
It captures four recurring themes of Leonardo's figures; an enigmatic smile, flowing curly hair, and a finger pointing to heaven, all defined by dense shadows.
Many copies of this painting have been made, particularly by Leonardo's pupils. Look For - The figure is wearing animal skins, and holding a reed cross. Experts believe these were added by a later painter. (BBC)