Leonardo da Vinci

The Louvre holds over twenty sheets by Leonardo — studies of hands, horses, the tilt of a woman's head, the flow of water. A single silverpoint line, set down and never corrected.

Painted on a refectory wall in an experimental technique that began flaking within decades. The fragility is part of the legend.

Probably a portrait of Lisa Gherardini, wife of a Florentine merchant. Leonardo carried it with him for years, reworking it endlessly, and it never left his side until his death in France. Her fame owes as much to theft as to genius: when Vincenzo Peruggia stole her in 1911 and kept her in a Paris apartment for two years, the empty wall drew larger crowds than the painting ever had.