Pope Gregory XIII

Lavinia Fontana - Portrait of Pope Gregory XIII

Gregorianscher Kalender Petersdom

Japanese Tensho Embassy with Pope Gregory XIII 1585

Gregory XIII medal

Pope Gregory XIII (Latin: Gregorius XIII; 7 January 1502 – 10 April 1585), born Ugo Boncompagni, was head of the Catholic Church and ruler of the Papal States from 13 May 1572 to his death in 1585. He is best known for commissioning the Gregorian calendar, which is still the internationally accepted civil calendar to this day.

Early Life

Ugo Boncompagni was born in Bologna, then part of the Papal States, in 1502. He studied law at the University of Bologna, where he became a professor of law. His academic and legal skills led to his appointment as a judge in the Roman Rota, the highest appellate tribunal of the Holy See.

Papacy

Boncompagni was elected pope on 13 May 1572, taking the name Gregory XIII. His pontificate was marked by efforts to implement the reforms of the Council of Trent, which aimed to address the challenges posed by the Protestant Reformation and to reform the church internally. He was also instrumental in promoting missionary work and established several seminaries for the training of priests.

Gregorian Calendar

One of Gregory XIII's most enduring contributions was the reform of the Julian calendar. The Julian calendar, introduced by Julius Caesar in 46 BC, had become increasingly inaccurate over the centuries. To correct this, Gregory XIII commissioned a group of astronomers and mathematicians, led by Aloysius Lilius and Christopher Clavius, to devise a new calendar. The result was the Gregorian calendar, introduced in 1582, which corrected the drift in the Julian calendar by omitting 10 days and adjusting the system of leap years. The new calendar was gradually adopted by countries around the world and remains in use today.

Diplomacy and Missions

Gregory XIII's papacy was also notable for its diplomatic activities. He sought to strengthen the Catholic Church's position in Europe and to counter the spread of Protestantism. He supported the Catholic League in France and backed the St. Bartholomew's Day Massacre of Huguenots in 1572, an event that has marred his legacy. Additionally, Gregory XIII was a patron of the arts and sciences, and he founded the Gregorian University in Rome.

Death and Legacy

Pope Gregory XIII died on 10 April 1585. His pontificate is remembered primarily for the introduction of the Gregorian calendar, which had a profound impact on the organization of time worldwide. Despite the controversies surrounding some of his actions, his contributions to the Catholic Church and his support for education and the sciences have also been recognized.