The siege of Florence took place from 24 October 1529 to 10 August 1530, at the end of the War of the League of Cognac. At the Congress of Bologna, the Medici Pope Clement VII and Emperor Charles V agreed to restore the Medici family in Florence. A large Imperial and Spanish army under Philibert of Châlon, Prince of Orange and Pier Maria III de' Rossi surrounded the city and after a siege of nearly ten months, captured it. They overthrew the Republic of Florence and installed Alessandro de' Medici as the ruler of the city.