Gregory XIII (1502-1585) was pope from 1572 to 1585. He was one of the more original and constructive popes of the 16th century, and his influence on religious life Europe and missionary activity overseas was impressive.
Ugo Boncompagni was born on Jan. 1, 1502, in Bologna. At the university there he acquired his doctorate in canon and civil law and then taught between 1531 and 1539. In 1539 he went to Rome. For 33 years before his election as pope he had wide experience in the papal service. Pope Paul al used his legal expertise widely. When about 40 years old, Boncompagni was ordained priest. Pope Paul IV employed him on several diplomatic missions and in 1558 appointed him bishop of Viesti. Pope Pius IV sent him to the last and most tumultuous period of the Council of Trent (1562-1563) and in 1565 created him a cardinal. Charles Borromeo, a paragon of the Tridentine reform, deeply influenced his religious attitudes. On May 14, 1572, he was elected pope and took the name Gregory XIII.
Simple in his style of life and sincerely pious, Gregory energetically advanced the Catholic Reformation. He insisted that bishops reside in their sees and fulfill their episcopal obligations. Convinced of the value of education, he founded at Rome several national colleges for the training of priests, the English, the Greek, the Maronite, the Armenian, and the Hungarian, joining the last to the already established German College. For the Roman College, which eventually became known as the Gregorian University in his honor, Gregory had a special predilection. He approved the Oratory of Philip Neri and the reform of the Carmelites by Theresa of Á vila. He charged Palestrina to revise the books of liturgical chant, and he supported the historical work of Baronius.
Gregory was most active in the fields of science and art. In 1582 he promulgated the revision of the calendar, supplanting the Julian with the Gregorian. He constructed the Quirinal Palace and the chapel named after him in St. Peter's Basilica. In diplomacy he took the initiative, giving permanent establishment to the system of resident papal nuncios. He tried, unsuccessfully, to bring about church union with Russia and Sweden. With the Maronites he renewed the old medieval ties.
In the fluid political life of Europe, Gregory supported the League in France, championed the cause of Mary Stuart in England, and recognized Stephen Báthory as king of Poland. The greatest weakness of his pontificate was his failure to eradicate the rash of brigandage in the Papal States. As a consequence, commerce and finance suffered seriously. Gregory died on April 10, 1585.
Further Reading on Gregory XIII
Even though recent research calls for some modifications, the best modern comprehensive study of Gregory XIII is Ludwig Pastor, History of the Popes, vols. 19 and 20, translated by Ralph F. Kerr (1930). It includes a full bibliography and list of sources.