Nazism aimed to transform the subjective consciousness of the German people—their attitudes, values and mentalities—into a single-minded, obedient "national community". The Nazis believed they would therefore have to replace class, religious and regional allegiances. Under the "Gleichschaltung" process, Hitler attempted to create a unified Protestant Reich Church from Germany's 28 existing Protestant churches. The plan failed, and was resisted by the Confessing Church. Persecution of the Catholic Church in Germany followed the Nazi takeover. Hitler moved quickly to eliminate political catholicism. Amid harassment of the Church, the Reich concordat treaty with the Vatican was signed in 1933, and promised to respect Church autonomy. Hitler routinely disregarded the Concordat, closing all Catholic institutions whose functions were not strictly religious. Clergy, nuns, and lay leaders were targeted, with thousands of arrests over the ensuing years.