To bolster his own new regime, Benito Mussolini was also eager for an agreement. After years of negotiation, in 1929, the Pope supervised the signing of the Lateran Treaties with the Italian government. According to the terms of the treaty that was one of the agreed documents, Vatican City was given sovereignty as an independent nation in return for the Vatican relinquishing its claim to the former territories of the Papal States. Pius XI thus became a head of state (albeit the smallest state in the world), the first Pope who could be termed a head of state since the Papal States fell after the unification of Italy in the 19th century. The concordat that was another of the agreed documents of 1929 recognised Catholicism as the sole religion of the state (as it already was under Italian law, while other religions were tolerated), paid salaries to priests and bishops, gave civil recognition to church marriages (previously couples had to have a civil ceremony), and brought religious instruction into the public schools. In turn, the bishops swore allegiance to the Italian state, which had a veto power over their selection. The Church was not officially obligated its support the Fascist regime; the strong differences remained, but the seething hostility ended. The Church especially endorsed foreign policies, such as support for the anti-Communist side in the Spanish Civil War, and support for the conquest of Ethiopia. Friction continued over the Catholic Action youth network, which Mussolini wanted to merge into his Fascist youth group.