He was ordained priest on December 20, 1879, and said his first Mass the following day in St. Charles on the Corse in Rome, He received his first appointment us doctor in the Ambrosian Library of Milan of which institute he w later to become prefect. He passe a ffreat many years carrying out his duties as assistant librarian and later prefect, From 1882-1013, Mgr. Ratti was) chaplain of a monastic institution in Blan, the convent of Our Lady of! the Cenacle. During this period of his life, he started a catechism class for working-class children in Milan, made up chiefly of little Milanese chimney-sweeps.
Me. atti did an immense amount of Worle at the Ambrosian Library in, examining codices, cataloguing volumes and writing learned treatises, especially about the works in the! Mbrary under his charge, Mgr. Ratti succeeded Cardinal Francis Ehrle as prefect of the Vatican Library in 1914, just before the outbreak of the World War, and remained in charge until May, 1918.
In September, 1014, Myr. Ratti was made a canon of the chapter of St. Peter's, while, in October, he was created supernumerary Apostolic Protonotary, He already had been made domestic prelate to His Holiness in March, 1907.
XV to take his place, and was made feardinal in June' of the same. year.
Pope Benedict XV died on January: 22, 1922 and Cardinal Ratti was chosen by the conclave to succeed him on February 6.
Pope Pius X1's reign as sovereign Pontiff was outstandingly notable for the conciliation effected between the [Church and the Ttalian State realized by the Lateran Treaty and Concordat} signed on February "11, 1929, in the Lateran Palace, Rome.
Several years of negotiations led to this agreement, which ended the dissensions between the Church Jand the Ialian State. That event was the most important during the papacy of Plus XX.
Text read from the printed page and cleaned; old type leaves the occasional error.