Pope Pius XI

Pope Pius XI (Ambrogio Damiano Achille Ratti) oversaw a period (1922-39) in which the Vatican became embroiled with numerous European powers. In 1929, Pius signed the Lateran Treaty with Mussolini, which secured an independent Vatican State. A deteriorating relationship led to the encyclical Non Abbiamo Bisogno (1931), in which he criticized the regime. Fearing the social upheaval of communist movements, Pius sided with Franco in Spain. After Germany utterly disregarded a 1933 concordat, Pius released a scathing indictment of National Socialism in Mit brennender sorge (1937), followed by the similarly-toned On Atheistic Communism. He went on to condemn all policies of racial discrimination. In 1931, he issued Quadragesimo Anno, in which he reiterated Leo XIII's denunciation of both socialism and unrestrained capitalism. Pius opposed the nascent ecumenical movement, instead pushing for Protestant and Orthodox denominations to reunite with Rome.