Pope Pius IX returns to Rome after a two-year exile. He had been forced to flee in disguise as an ordinary priest, traveling to the Italian city of Gaeta.
Although the Roman Republic created in 1849 guaranteed the pope's position as leader of the Catholic Church, they also granted full civil and political equality to adherents of all religions, including Judaism.
This was intolerable to Pius IX because treating Jews as civil and political equals implies that Judaism is the equal of Catholic Christianity. It contradicts the traditional Christian doctrine that Christianity superseded Judaism and that therefore Judaism is no longer an entirely valid religion. It may have been valid at one time, but today Jews are obliged to convert to Christianity.