Galeazzo Maria Sforza was the fifth Duke of Milan from 1466 until 1476. He was born to Francesco Sforza, a popular condottiero and ally of Cosimo de' Medici who would gain the Duchy of Milan in 1450, and Bianca Maria Visconti, Duchess of Milan on her own right. Sforza was betrothed into the Gonzaga family; after the engagement with Dorotea Gonzaga was called off, he married Bona of Savoy.