1904 – 1907: Priest at Qrendi.
1907 – 1933: Director of Fra Diegu Institute, Hamrun.
1910 – 1933: Superior of the Society of St. Paul.
1911 – 1933: Monsignor of the Metropolitan Cathedral of Malta.
1915 – 1918: General Secretary of Archbishop Maurus Caruana.
1918 – 1920: Rector of the Major Seminary at Mdina.
1918 – 1921: Contributed towards the drafting of the Constitution of Malta.
1919 Peacemaker in the 7 giugno affair.
1920 – 1933: Dean of the Metropolitan Chapter.
1922 Acted as parish priest at the Gudja parish.
1922 – 1933: Director of St. Joseph’s Institute, St. Venera.
1922 – 1933: Director of Jesus of Nazareth Institute, Zejtun.
1925 – 1933: Director of St. Joseph’s Institute, Ghajnsielem, Gozo.
1925 – 1933: Director of the House for Infants, St. Venera.
1927 – 1933: Director of St. Francis de Paule Institute, B’Kara
1928 – 1931: Director of the Sacred Heart of Jesus Laboratory, Valletta.
1930 Mediator between Lord Strickland and the Church.
1932 – 1933: Senator in the Third Parliament.
1910: Founding and opening of the first house in St. Roque Street, Mdina.
1919: Proposal is made to the Founder to get a house at Zabbar.
1921: The Founder asks the Canons of St. Paul’s Grotto, Rabat, for part of the ‘College’. They give him no for an answer.
1921: The Society leaves the first house and goes to live in a part of Xara Palace, Mdina.
1921: The canonical approval of the Society by the diocesan decree “Auctoritate Nostra Ordinaria”.
1922: The Founder starts publishing “San Pawl: Almanac ta’ 1-Istitut tal-Missioni”.
1922: The members of the Society take over St. Joseph’s Institute instead of the De la Salle Brothers.
1923: Acceptance of St. Agatha’s Church, Hal Bajjada, Rabat.
1924: Acceptance, with some conditions, of the Rules of the Society of St. Paul.
1925: Opening of St. Joseph’s Institute, Ghajnsielem, Gozo. Society in charge.
1927: Donation of the Oratory at B’Kara to the Society.
1927: Br. Joseph Caruana SSP goes to Somalia, Abyssinia.
1932: Diocesan approval of the Rules, without any condition.
1932: Laying of the foundation stone of St. Agatha’s Mother-house.
1933: Inauguration of part of the House.
Family De Piro: Original documents or copies related to the De Piro family but which do not have any direct relationship with Monsignor.
De Piro: Sketches of his boyhood: These are original sketches of Giuseppe De Piro as a young boy and until he started studying for the priesthood.
De Piro Documents: Documents related to Giuseppe De Piro but which have nothing to do with the Missionary Society of St. Paul.
Correspondence between Giuseppe De Piro and his mother Ursola: Letters exchanged between mother and son when the latter was in Rome (1898 – 1902).
Family letters to young Giuseppe De Piro: Letters which Giuseppe received from his brothers and sisters when he was still young and away from Malta.
Letters to young De Piro: Letters Giuseppe received from different persons from the time he was at the Lyceum in Malta up to his stay in Davos, Switzerland (1889 – 1904).
M.S.S.P. at the time of the Founder: A collection of documents and letters to and from Monsignor related to the various periods of the M.S.S.P. history. Almost all the letters are from or to Monsignor (1908 – 1933).
Personal Documents M.S.S.P.: Documents related to taking of the habit, professions, courses, ordinations and correspondence of the members of the M.S.S.P.
Interviews about Mgr. De Piro: Information obtained from those who knew Monsignor directly.
Diary of Mgr. De Piro: Personal notes of De Piro himself from the time he started studying for the priesthood until he clarified his ideas about the nature of the Society he wanted to found. Years covered: 1898 – 1909. Almost each and every entry is related to the Missionary Society.
Atti del Consiglio del Padre Preposto della Compagnia di San Paolo: Years covered: 1927 – 1933. These are the official acts of the first council of the Society of St. Paul. Helping Mgr. De Piro there were Fr. Michael Callus and Fr. Joseph Spiteri.
Mgr. De Piro, Dean of the Cathedral of Malta: Mainly photo-copies of the acts of the Chapter of the Cathedral, where De Piro gave his share.
Rector of the Major Seminary: Original documents and photo-copies related to the years 1918 – 1920 when Monsignor was rector of the Major Seminary at Mdina.
Fra Diegu Institute: The documents related to Monsignor as director of this Institute. Years 1907 – 1933.
St. Joseph’s Institute: Documents related to De Piro as director of this Institute. Years 1924 – 1933.
St. Joseph’s Institute, Ghajnsielem – Gozo: Material related to
Monsignor as director of this Institute. Years 1924 – 1933.
The Oratory at B’Kara: A collection of documents related to the history of the Oratory from its beginning until the time it was handed over to De Piro in order to be run by his Society. Years 1910 – 1933.
Sacred Heart of Jesus Laboratory: The documents which show Monsignor’s efforts to create an initiative in favour of poor and abandoned young girls. Years 1927 – 1931.
Missionary Sisters of Jesus of Nazareth: The documents which witness De Piro’s efforts in helping with the founding of this Maltese Missionary Congregation for Sisters. Years 1925 – 1933.
Appunti di Predicazione di Mons. De Piro: Whole or parts of sermons written by Monsignor himself.
Corrispondenza riguardante la Fondazione della Missione Somala-Maltese: A great number of letters written or received by De Piro himself. Several of them have been written by Br. Joseph Caruana SSP to the Founder or vice-versa. Years 1927 – 1933.
Sant’Agata: Procura del Barone De Piro: Documents related to the administration of St. Agatha’s Church, Rabat. Years: 1812 until it was passed on to Baron De Piro.
Conti Chiesa di Sant’Agata: Documents showing the passing on of the church to the Society of St. Paul.
Acquisto siti attigui a S. Agata – Rabat: Documents showing the acquisition of land on which St. Agatha’s Motherhouse is built.
Miscellanea: All other documents.