Lucrezia Crivelli in the context of La belle ferronnière

La Belle Ferronnière (French pronunciation: [la bɛl fɛʁɔnjɛʁ]) is a portrait painting of a lady, by Leonardo da Vinci, in the Louvre. It is also known as Portrait of an Unknown Woman. The painting's title, applied as early as the seventeenth century, identifying the sitter as the wife or daughter of an ironmonger (a ferronnier), was said to be discreetly alluding to a reputed mistress of Francis I of France, married to a certain Le Ferron. Later she was tentatively identified as Lucretia Crivelli, a married lady-in-waiting to Duchess Beatrice of Milan, who became another of the Duke's mistresses.

Leonardo's Lady with an Ermine has also been known by this name. This was once believed to be a portrait of Cecilia Gallerani, one of the mistresses of Ludovico Sforza, Duke of Milan. The narrative and the title were applied to Lady with an Ermine when it was in Princess Izabela Czartoryska's collection, and became confused with La Belle Ferronnière by the presence of a ferronnière, a type of accessory worn across the forehead, in the painting as well.

Giovanni Paolo I Sforza (March 1497 – December 1535) was an Italian condottiero, the first in the Sforza family line of the Marquesses of Caravaggio.

He was a legitimized son of Ludovico il Moro, duke of Milan, and Lucrezia Crivelli. In 1513, when his half-brother Massimiliano shortly restored the family seignory in Milan, he took part in the defence of Novara against the French. When his other half-brother Francesco II made a similar attempt (1525), Giovanni Paolo was besieged in the Castello Sforzesco by the Spaniards under Antonio de Leyva; three years later he was again besieged by them in Lodi, this time with victorious results.