The Lady with an Ermine is a portrait painting by the Italian Renaissance artist Leonardo da Vinci. Dated to c. 1489–1491, the work is painted in oils on a panel of walnut wood. Its subject is Cecilia Gallerani, a mistress of Ludovico Sforza ("Il Moro"), Duke of Milan; Leonardo was painter to the Sforza court in Milan at the time of its execution. It is the second of only four surviving portraits of women painted by Leonardo, the others being Ginevra de' Benci, La Belle Ferronnière and the Mona Lisa.

https://en.wikipedia.org/wiki/Lady_with_an_Ermine