GREGORY XIII. (_Ugo Buoncompagno_), pope from 1572 to 1585, was born on the 7th of January 1502, in Bologna, where he received his education, and subsequently taught, until called to Rome (1539) by Paul III., who employed him in various offices. He bore a prominent part in the council of Trent, 1562-1563. In 1564 he was made cardinal by Pius IV., and, in the following year, sent to Spain as legate. On the 13th of May 1572 he was chosen pope to succeed Pius V. His previous life had been rather worldly, and not wholly free from spot; but as pope he gave no occasion of offence. He submitted to the influence of the rigorists, and carried forward the war upon heresy, though not with the savage vehemence of his predecessor. However, he received the news of the massacre of St Bartholomew (23rd of August 1572) with joy, and publicly celebrated the event, having been led to believe, according to his apologists, that France had been miraculously delivered, and that the Huguenots had suffered justly as traitors. Having failed to rouse Spain and Venice against the Turks, Gregory attempted to form a general coalition against the Protestants. He subsidized Philip II. in his wars in the Netherlands; aided the Catholic League in France; incited attacks upon Elizabeth by way of Ireland. With the aid of the Jesuits, whose privileges he multiplied, he conducted a vigorous propaganda. He established or endowed above a score of colleges, among them the Collegium Romanum (founded by Ignatius Loyola in 1550), and the Collegium Germanicum, in Rome. Among his noteworthy achievements are the reform of the calendar on the 24th of February 1582 (see CALENDAR); the improved edition of the _Corpus juris canonici_, 1582; the splendid Gregorian Chapel in St Peter's; the fountains of the Piazza Navona; the Quirinal Palace; and many other public works. To meet the expenses entailed by his liberality and extravagance, Gregory resorted to confiscation, on the pretext of defective titles or long-standing arrearages. The result was disastrous to the public peace: nobles armed in their defence; old feuds revived; the country became infested with bandits; not even in Rome could order be maintained. Amid these disturbances Gregory died, on the 10th of April 1585, leaving to his successor, Sixtus V., the task of pacifying the state. See the contemporary lives by Cicarella, continuator of Platina, _De vitis pontiff. Rom._; Ciaconius, _Vitae et res gestae summorum pontiff. Rom._ (Rome, 1601-1602); and Ciappi, _Comp. dell' attioni e santa vita di Gregorio XIII_ (Rome, 1591). See also Bompiano, _Hist. pontificatus Gregorii XIII._ (Rome, 1655); Ranke, _Popes_ (Eng. trans., Austin), i. 428 seq.; v. Reumont, _Gesch. der Stadt Rom._ iii. 2, 566 seq.; and for numerous references upon Gregory's relation to the massacre of St Bartholomew, _Cambridge Mod. Hist._ iii. 771 seq.