Gregory XIII, pope (1572-1585), born Ugo Buoncampagno February 7, 1502, at Bologna, where he studied law and graduated in 1530, and afterwards 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 frst judge of the capital, abbreviator, and vice-chancellor of the campagna; by Paul IV he was attached as datarius to the suite of Cardinal Carafa; and by Pope Pius IV he was created cardinal priest and sent to the council of Trent.
On the death of Pius IV in May 1572, the choice of the conclave fell upon Buonocampagno, 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 thses and similar objects, he confiscated a large proportion 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 ones, 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. Gregory XIII was succeeded by Sixtus V
from the 9th edition (1880) of an unnnamed encyclopedia