The Reichskonkordat is a treaty between the Holy See and Germany negotiated during its transition into Nazi Germany. It was signed on 20 July 1933 by Secretary of State Eugenio Pacelli (later Pope Pius XII) on behalf of Pope Pius XI and Vice Chancellor Franz von Papen on behalf of President Paul von Hindenburg and the German government. It was ratified September 10, 1933 and has been in force since this date. The treaty guarantees the rights of the Roman Catholic Church in Germany. When bishops take office Article 16 states they're required to take an oath of loyalty to the Governor or President of the German Reich established according to the constitution. The treaty also requires all clergy to abstain from working in and for political parties. Nazi breaches of the agreement began almost as soon as it had been signed and intensified afterwards leading to protest from the Church including in the 1937 Mit brennender Sorge encyclical of Pope Pius XI. The Nazis planned to eliminate the Church's influence by restricting its organizations to purely religious activities.