 After his election , he made Luigi Maglione his successor as Cardinal Secretary of State . Cardinal Maglione , a seasoned Vatican diplomat , had reestablished diplomatic relations with Switzerland and was for many years nuncio in Paris . Yet , Maglione did not exercise the influence of his predecessor Pacelli , who as Pope continued his close relation with <unk> Montini ( later Pope Paul VI ) and Domenico Tardini . After the death of Maglione in 1944 , Pius left the position open and named Tardini head of its foreign section and Montini head of the internal section . Tardini and Montini continued serving there until 1953 , when Pius XII decided to appoint them cardinals , an honor which both turned down . They were then later appointed to be Pro @-@ Secretary with the privilege to wear Episcopal Insignia . Tardini continued to be a close co @-@ worker of the Pope until the death of Pius XII , while Montini became archbishop of Milan , after the death of Alfredo Ildefonso Schuster . 
