After his election as pope in 1922, Pius XI appointed Orsenigo to the rank of titular archbishop of Ptolemais and made him nuncio to the Netherlands, effective 23 June 1922.

[6] On 25 April 1930, he became Apostolic Nuncio in Germany, a post previously held by Eugenio Pacelli (future Pope Pius XII), who had been appointed Cardinal.

[7] On 16 February 1933, Orsenigo wrote to Pacelli that it would be "ingenuous and incoherent" to support the newly elected Nazi government, but that he feared open opposition would lead to a new Kulturkampf.

[8] As early as March 1933, Orsenigo concluded that compromise and conciliation was the only option, arguing that earlier condemnations of Nazism by German bishops had concerned only its religious, not political, tenets.

[2] Following an 4 April 1933 transmission from Pope Pius XI to "look into whether and how it might be possible to become involved" in helping the victims of Nazi persecution, Orsenigo replied that any intervention would be seen as "a protest against that government's law" and thus not be advisable.

[11] Orsenigo reported that Hitler did not agree with the neo-pagan wing of the Nazi party, as represented in Alfred Rosenberg's The Myth of the Twentieth Century.

Pius XII retained Orsenigo as nuncio to Germany; according to Phayer, the pope's priorities were the preservation of the Reichskonkordat specifically, and Vatican-German relations more generally.

[14] In a 1940 note to Pius XII, Orsenigo again argued in favor of conciliation, stating his fears of lapsed religiosity among German Catholics unless the clergy appeased the regime and relieved members of the Church of a conflict of conscience.

A rare exception, was the Nazi plan to "resettle" Jews married to Christians, although Phayer argues that his concern was primarily with their Catholic spouses.

[12] In 1941, Orsenigo was contacted by Kurt Gerstein, a Protestant SS officer who had personally witnessed the extermination of Jews and wished to notify the Vatican.

[21] Pius XII therefore reversed his decision not to replace Polish prelates with (even temporary) German ones, naming Karl Maria Splett, the bishop of Danzig, also apostolic administrator of Chełmno-Pelpin.

[12] It is unknown whether Orsenigo himself was aware of his assistant's party membership, however this fact was certainly known by Robert Leiber, a German Jesuit who served as one of Pius XII's closest confidants and advisers during the war.

[7] The nunciature lost its official status in May 1945, with the defeat of Nazi Germany, although the Allied Control Council allowed Orsenigo to remain in Eichstätt.

Orsenigo died in Eichstätt on 1 April 1946, leaving his aide de camp, Monsignor Carlo Colli as the only remaining link between Pius XII and the German Church.

[7] After a lengthy interregnum, during which Pius XII relied on Father Igo Ziegler at the Villa Grosch in Kronberg, the next nuncio would be Aloisius Joseph Muench.

[25] According to Prof. Jose Sánchez, "a chief point of criticism of Pope Pius XII is his unwillingness to replace Cesare Orsenigo as his nuncio to Berlin".