Elected deputy in 1849, he worked strenuously for the national cause, supporting political Right, and in 1867 and again in 1869 he held the portfolio of education; he played an important part in the events consequent upon the occupation of Rome by Italy and helped to draft the Law of Guarantees.
12.
During this long period he was called upon to conduct the delicate negotiations connected with the Franco-German War, the occupation of Rome by the Italians, and the consequent destruction of the temporal power of the Pope, the Law of Guarantees and the visits of Victor Emmanuel II to Vienna and Berlin.
13.
Italy's "'Law of Guarantees "', passed by the senate and chamber of the Italian parliament on 13 May 1871, accorded the Pope certain honors and privileges similar to those enjoyed by the King of Italy, including the right to send and receive ambassadors who would have full diplomatic immunity, just as if he still had temporal power as ruler of a state.
14.
After the September Convention of 1864, Antonelli organized the Legion of Antibes to replace French troops in Rome, and in 1867 secured French aid against temporal power ), and obtained from the Italians payment of the Peter's pence ( 5, 000, 000 lire ) remaining in the papal exchequer, as well as 50, 000 scudi, the only installment of the Italian allowance ( subsequently fixed by the Law of Guarantees, March 21, 1871 ) ever accepted by the Holy See.
