For 10 points, name this North Italian city, a rival of Venice and Florence.
The "Captains and Defenders" headed one short-lived government in this city, which was able to take back such cities as Lodi and Piacenza. This home of the Golden Ambrosian Republic was led by Gian Galeazzo and Filippo Maria, the strongest and last members of its Visconti family. Francis I won this city after Swiss mercernaries failed to defend it, ending the rule of one family headed by Francesco I. The Sforzas ruled this country that led the Lombard League against Frederick Barbarossa. For 10 points, name this North Italian city, a rival of Venice and Florence.
The "Captains and Defenders" headed one short-lived government in this city, which was able to take back such cities as Lodi and Piacenza.
{Milano}