Before and during World War II, Nazi propaganda and ideology made frequent use of the Teutonic Knights' imagery, as the Nazis sought to depict the Knights' actions as a forerunner of the Nazi conquests for Lebensraum. Heinrich Himmler tried to idealise the SS as a 20th-century reincarnation of the medieval Order. Yet, despite these references to the Teutonic Order's history in Nazi propaganda, the Order itself was abolished in 1938 and its members were persecuted by the German authorities. This occurred mostly due to Hitler's and Himmler's belief that, throughout history, Roman Catholic military-religious orders had been tools of the Holy See and as such constituted a threat to the Nazi regime.