Painted between 1495 and 1499, "La Belle Ferronnière" is a masterpiece from Leonardo da Vinci's Milanese period and stands as one of his few surviving portrait panels. The identity of the sitter remains a subject of ongoing historical debate; she is widely believed to be Lucrezia Crivelli, a mistress of Ludovico Sforza, the Duke of Milan. The painting's title derives from the delicate headband jewel, a ferronnière, worn across her brow. The portrait exemplifies Leonardo’s mastery of sfumato, utilizing subtle gradations of shadow to bestow a remarkable sense of three-dimensional volume and psychological depth to her expression. Her three-quarter pose, combined with a guarded, enigmatic gaze directed away from the viewer and behind a structural parapet, accentuates her aristocratic distance and emotional complexity. Executed in oil on a walnut panel, the painting is housed in the Musée du Louvre in Paris.