tle of Desio (1277), he won the city for his family. The Visconti succeeded in ousting the della Torre forever, ruling the city and its possession until the 15th century.
Much of the prior history of Milan was the tale of the struggle between two political factions—the Guelphs and the Ghibellines. Most of the time the Guelphs were successful in the city of Milan. However, the Visconti family were able to seize power (signoria) in Milan, based on their "Ghibelline" friendship with the German Emperors. In 1395, one of these emperors, Wenceslas (1378–1400), raised the Milanese to the dignity of a duchy. Also in 1395, Gian Galeazzo Visconti became duke of Milan. The Ghibelline Visconti family was to retain power in Milan for a century and a half from the early 14th century until the middle of the 15th century.
In 1447 Filippo Maria Visconti, Duke of Milan, died without a male heir; following the end of the Visconti line, the Ambrosian Republic was enacted. The Ambrosian Republic took its name from St. Ambrose, popular patron saint of the city of Milan. Both the Guelph and the Ghibelline factions worked together to bring about the Ambrosian Republic in Milan. However, the Republic collapsed when in 1450, Milan was conquered by Francesco Sforza, of the House of Sforza, which made Milan one of the leading cities of the Italian Renaissance.
Early modern
The French king Louis XII first laid claim to the duchy in 1492. At that time, Milan was defended by Swiss mercenaries. After the victory of Louis's successor Francis I over the Swiss at the Battle of Marignano, the duchy was promised to the French king Francis I. When the Habsburg Charles V defeated Francis I at the Battle of Pavia in 1525, northern Italy, including Milan, passed to the House of Habsburg.
In 1556, Charles V abdicated in favour of his son Philip II and his brother Ferdinand I. Charles's Italian possessions, including Milan, passed to Philip II and the Spanish
