Columbia subject headings:
Harvard subject headings:
Benedict XV, Pope, 1854-1922
Catholic Church--Foreign relations--Germany.
Germany--Church history--20th century.
Germany--Foreign relations--Catholic Church.
Germany--History--1918-1933.
Pius XI, Pope, 1857-1939
Princeton subject headings:
Catholic Church--Foreign relations--Germany.
Church and state--Germany--History--20th century.
Germany--Foreign relations--Catholic Church.