ANS – Autograph Note Signed and dated, 1972, on his biglietto (oversized card). Several words of greeting in the handwriting of Marella.  Accompanied by original mailing envelope also in the hand of Marella (reverse bears the imprint Secretariatus Pro Non Christianis).
 
From 1922 to 1924, Marella was an official of the Sacred Congregation for the Propagation of the Faith in the Roman Curia. He was raised to the rank of Privy Chamberlain of His Holiness on 9 January 1923, and later Domestic Prelate of His Holiness on 5 April 1933. He then served as auditor (1924–1933) and chargé d’affaires (February to September 1933) of the Apostolic Delegation to the United States.
On 15 September 1933, Marella was appointed Titular Archbishop of Doclea by Pope Pius XI. He received his episcopal consecration on the following 29 October from Cardinal Pietro Fumasoni Biondi, with Archbishops Carlo Salotti and Domenico Spolverini serving as co-consecrators, at the chapel of Collegio de Propaganda Fide in Rome. Marella was named Apostolic Delegate to Japan the next day, on 30 October. In 1942, when the Vatican accepted de facto diplomatic relations with Japan, Marella was given “full diplomatic privileges”.[1] He was made Apostolic Delegate to Australia, New Zealand, and Oceania on 27 October 1948.
 
Also in the 1940s, Marella was sent to France as an agent of Pope Pius XII when he was aiming to stamp out the Worker-Priest movement that the Pope believed Cardinal Emmanuel Célestin Suhard had been supporting despite his protests otherwise. Although Suhard’s death in 1949 greatly eased Pius’s task, it was not until Marella succeeded Archbishop Angelo Roncalli (the future Pope John XXIII) as Nuncio to France on 15 April 1953 that the suppression was completed.
 
Pope John XXIII created Cardinal-Priest of Sant’Andrea delle Fratte in the consistory of 14 December 1959. Appointed Archpriest of St. Peter’s Basilica and Prefect of the Sacred Congregation of the Fabric of St. Peter’s Basilica on 14 August 1961, Marella attended the Second Vatican Council from 1962 to 1965, and was one of the cardinal electors who participated in the 1963 papal conclave, which selected Pope Paul VI.
Papal legate to the inauguration of the Vatican pavilion at the New York World’s Fair 1964, presiding over the unveiling of the Pietà and presenting Cardinal Francis Spellman with a topaz pectoral cross once worn by Pius XII as (gift from Pope Paul VI).  Marella was the recipient of four honorary doctorates, including one from the Catholic University of America.
 
President of the Secretariat for Non-Christians 1964, and again served as a papal legate, to the eighth centennial celebration of the erection of Notre-Dame Cathedral in Paris (27 May 1964), to the centennial celebration for the arrival of the first Catholic missionaries in Japan in Tokyo (12 January 1965), and to the National Congress of the Confederation of the Christian Doctrine in Pittsburgh (28 August 1966).
 
In 1970, Marella served as the papal representative to Expo ’70 in Osaka. His career then wound down during the 1970s, and he resigned his presidency of the Secretariat at the end of February 1973, whilst two years later he lost the right to vote in a papal conclave on reaching eighty. From 12 December 1977 until his death Marella was vice-dean of the Sacred College of Cardinals.1895