 Despite Vatican pessimism and a lack of visible progress , Pacelli continued the secret negotiations , until Pius XI ordered them to be discontinued in 1927 . Pacelli supported German diplomatic activity aimed at rejection of punitive measures from victorious former enemies . He blocked French attempts for an ecclesiastical separation of the Saar region , supported the appointment of a papal administrator for Danzig and aided the reintegration of priests expelled from Poland . A Prussian Concordat was signed on 14 June 1929 . Following the Wall Street Crash of 1929 , the beginnings of a world economic slump appeared , and the days of the Weimar Republic were numbered . Pacelli was summoned back to Rome at this time — the call coming by telegram when he was resting at his favourite retreat , the Rorschach convent sanatorium . He left Berlin on 10 December 1929 . David Dalin wrote " of the forty @-@ four speeches Pacelli gave in Germany as papal nuncio between 1917 and 1929 , forty denounced some aspect of the emerging Nazi ideology . " In 1935 he wrote a letter to the bishop of Cologne describing the Nazis as " false prophets with the pride of Lucifer . " and as " bearers of a new faith and a new Evangile " who were attempting to create " a mendacious antimony between faithfulness to the Church and the Fatherland " . Two years later at Notre Dame in Paris he named Germany as " that noble and powerful nation whom bad shepherds would lead astray into an ideology of race . " 
