The Lady with an Ermine is one of Leonardo da Vinci’s most captivating portraits, painted around 1489–1490 in Milan. It features Cecilia Gallerani, a young woman who was the mistress of Ludovico Sforza, the Duke of Milan and Leonardo’s patron. The Lady with Ermine is an oil painting on canvas, measuring 54 cm (21 in) tall and 40 cm (16…