Italy remains majority Catholic, around 78 to 80 percent by most estimates including Pew Research's Religious Composition of the World, 2010-2020, though religious practice has declined significantly and religiously unaffiliated Italians now form a substantial and growing minority, alongside small Muslim, Protestant and Orthodox Christian communities. Rome has been the seat of the Catholic papacy since antiquity, and the Vatican, an independent city-state since the 1929 Lateran Treaty resolved decades of dispute following the loss of the Papal States during Italian unification in 1870, sits within Italy's capital as the church's sovereign headquarters.
Italy's religious landscape reflects deep regional variation, from the historically strong Catholic institutional presence in the south and the Veneto to more secular traditions in parts of the industrial north, and the country's Waldensians, one of Europe's oldest surviving pre-Reformation dissenting Christian movements founded in the twelfth century, maintained a persecuted minority presence for centuries before gaining full legal equality only in the twentieth century. Italy's ancient Jewish community, one of Europe's oldest with continuous presence since Roman times, suffered severe persecution under Mussolini's 1938 racial laws and the subsequent Holocaust deportations after the German occupation from 1943.