The Reich Concordat was an agreement signed between the Vatican and the National Socialist government of Germany. The person primarily responsible for the negotiation and signing of this document was the Cardinal Secretary of State, Eugenio Pacelli, the future Pope Pius XII with the agreement of Pius XI.

Pacelli was a firm believer in the unchallenged authority of the Pope as the head of the Catholic Church. For this reason, he had long aimed to establish a formal agreement between the Vatican and Germany, and impose upon the country’s Catholic population the pope’s authority. The German Catholics were one of the most powerful, influential and wealthy Catholic communities around the world. Pacelli wished to establish a power relationship with the local clergy that would heavily favor the Vatican. He aimed to do so through the imposition of the Canon Code of Law, a definition of Church laws that was published and brought into force in 1917; this interpretation of Church law encouraged the supremacy and absolutism of the pontiff over the local clergy.

The Concordat allowed the papacy to impose the new laws on the German clergy, and gained special privileges for Catholic schools and organizations. Pacelli also hoped that the agreement would safeguard against Nazi encroachments on and persecution of the German Catholic minority. In exchange, the Vatican would ‘encourage’ the local Catholic clergy and faithful to ‘voluntarily’ withdraw from politics, going as far as disbanding its powerful Catholic Center Party. This effectually destroyed any political opposition against the Nazis. This guarantee of nonintervention left Hitler and the Nazis free to pursue their anti-Semitic policies. 

Pacelli’s fear of Catholic persecution raises an interesting controversy. As one of the most powerful and faithful communities in Germany, the Catholics should have had little to fear from the Nazis especially as early as 1933. The matter is further complicated by the historic success of Catholic resistance against government persecution in Germany such as that against Bismarck’s Kulturkampf, arguably a more systematic and powerful persecuting force than what the Nazis could have been in 1933. The Kulturkampf or "culture struggle" was a policy formulated by Bismarck, partly as a reaction to the dogma of infallibility. Under this program, the entire Catholic community of Germany was systematically persecuted, and much of the clergy and its work were submitted to state interference. 

Even as late as 1942, the German Catholic community was a powerful social force. The opposition of the Catholics to the Nazi euthanasia program helped hasten its end and whatever was left had to moved underground. The organization and success of the Jesuits as the ‘secret army’ of the Vatican was another aspect that was feared and greatly admired by the Nazis. Himmler went as far as to model the SS after the Jesuits and believed them to be the most successful intelligence gathering organization in the world, and hence, one to be greatly feared.

Eventually, the reluctance of the Vatican to encourage Catholic opposition against the Nazis and their policies served as a silent endorsement of their policies. The moral base for protest for the Catholics was further compromised with the silence of Pius XII even when the terms of the Concordat were repeatedly violated by the Nazis. The reticence of the Pope in publicly denouncing Nazi anti-Semitism and his failure to publish "The Lost Encyclical" of Pius XI are seen by at least one historian as a violation of the moral obligations of his role.