The founder of the Sforza dynasty was Muzio Attendolo Sforza (1369–1424). The son of a peasant family, he became a successful condottiere, a professional soldier for hire. In the course of his career, he fought for many employers, including the Visconti family, who ruled the city of Milan. When Muzio died in battle, his son Francesco (1401–1466) succeeded him as commander of his troops. While employed by Queen Giovanna of Naples, he left to fight for the Visconti against the Venetians. He was dismissed when the Visconti grew suspicious of his loyalties. But they soon needed him back, and as an inducement, he was promised the Visconti heir, Bianca Maria, as his wife. Mutual distrust still prevailed between Francesco and his future father-in-law, Filippo Maria, and it was years before the marriage took place. When Filippo died, Francesco wanted Filippo's dukedom. He ended up laying siege to Milan, which surrendered to him in 1450. He became a highly respected duke. He had numerous illegitimate children, as well as four children by Bianca Maria.
Francesco was succeeded by his son Galeazzo Maria, a cruel and dissolute ruler who was assassinated in 1476. Galeazzo Maria's heir, Gian Galeazzo, was only eight years old at the time, and it was Galeazzo Maria's brother Ludovico who finally controlled Milan after the resulting power struggle. Although he was supposedly Gian Galeazzo's guardian, Ludovico refused to give up power when Gian married Isabella of Naples in 1489, and a feud with Naples ensued. Ludovico began courting the French king, Charles VIII, who had claims to Naples, in the hope that Charles would put an end to his troubles with Naples and with rival Venice. When Gian Galeazzo conveniently died soon after Charles' invasion in 1494, Ludovico become the uncontested ruler of Milan.
