GREGORY XIII. (Ugo Buoncompagno), pope from 1572 to 1585, was born February 7, 1502, at Bologna, where he studied law and graduated in 1530, and after-wards taught jurisprudence for some years, Alexander Farnese and Charles Borromeo being among his pupils. At the age of thirty-six he was summoned to Rome by Paul III., under whom he held successive appointments as first judge of the capital, abbreviator, and vice-chan-cellor of the campagna; by Paul IV. he was attached as datarius to the suite of Cardinal Carafa; and by Pius IV. he WHS created cardinal priest and sent to the council of Trent. On the death of Pius V. in May 1572, the choice of the conclave fell upon Buoncompagno, who assumed the name of Gregory XIII. His intervention in the affairs of Britain through Ireland and by means of his tool Philip II., and also the league which he sought to cement against France (the massacre of the St Bartholomew had taken place in September 1572), are matters which belong to the history of those countries. In order to raise funds for these and similar objects, he confiscated a large propor-tion of the houses and properties throughout the states of the church,—a measure which enriched his treasury, indeed, for a time, but by alienating the great body of the nobility and gentry, revived old factions, created new anes, and ultimately plunged his temporal dominions into a state bordering upon anarchy. Such was the position of matters at the time of his death, which took place on the 10th of April 1585. He was a liberal patron of the Jesuit order, for which he founded many new colleges; the new and greatly improved edition of the Corpus juris canonici was also due to his care; but the work with which the name of Gregory XIII. is most intimately and honourably associated is that of the reformation of the calendar, which has been already described under that heading (vol. iv. p. 671). Gregory XIII. was succeeded by Sixtus V.