In 1521 Parma was added to his rule, and in 1523 he was appointed viceregent of Romagna by Clement VII.
He concluded a concordat with Rudolph of Habsburg in May 1278, by which the Romagna and the exarchate of Ravenna were guaranteed to the pope; and in July he issued an epochmaking constitution for the government of Rome, which forbade foreigners taking civil office.
Summoned to Paris by Cavour in 1856 to prepare the memorandum on the Romagna provinces for the Paris congress, he was in 1859 appointed by Cavour secretary-general of the Piedmontese Foreign Office.
In the same year he was elected president of the assembly of the Romagna after the rejection of pontifical rule by those provinces, and prepared their annexation to Piedmont.
See C. Ricci, "Della Chiesa e castello di Polenta" in Atti e Memorie della Deputazione di Storia patria per le prooniae di Romagna, ser.