A painting kept in a Swiss bank vault is claimed by some to be a lost painting by Leonardo da Vinci (1452-1519). In 1499, Isabella d’Este asked Leonardo to paint her portrait. A drawing, now kept in the Louvre, is the result of that request. Scholars have wondered whether Leonardo ever used the sketch to complete a portrait, with many assuming that he never executed a painting. Scientific tests have dated the newly discovered portrait between 1460 and 1650, but the work could easily have been made by a student, follower, or copyist at work in the sixteenth or seventeenth century. While some specialists are convinced, others are skeptical that the work, which seems to show Isabella in the guise of St. Catherine of Alexandria, was in fact painted by Leonardo himself.