After defeating the papal army on 18 September 1860 at the Battle of Castelfidardo, and on 30 September at Ancona, Victor Emmanuel II of Sardinia took all the Papal territories except Latium with Rome and took the title King of Italy. Rome itself was invaded on 20 September 1870 after a few-hours siege. Italy instituted the Law of Guarantees (13 May 1871) which gave the Pope the use of the Vatican but denied him sovereignty over this territory, nevertheless granting him the right to send and receive ambassadors and a budget of 3.25 million liras annually. Pius IX officially rejected this offer (encyclical "Ubi nos", 15 May 1871), since it was a unilateral decision which did not grant the papacy international recognition and could be changed at any time by the secular parliament.