Pope Gregory XIII (226º): Vatican I & Dogma & Gregorian Calendar — Complete Guide
Pontificate: 13 May 1572–10 April 1585
Gregory XIII was the 226th pope of the Catholic Church, reigning 13 May 1572–10 April 1585 during the Renaissance papacy. First pope to bestow the Immaculate Conception as the patron saint of the Philippine Islands through the bull Ilius Fulti Praesido (1579).
Who Was Pope Gregory XIII?
This biography of Gregory XIII (226º) covers background, major events, and legacy in the line of St. Peter. Common search topics include Vatican I & Dogma, Gregorian Calendar. During the Renaissance papacy, the Bishop of Rome exercised teaching, sanctifying, and governing authority for the universal Church.
Early Life & Background
Before election he was known as Ugo Boncompagni. Born 7 January 1502 Bologna, Papal States, he entered a world shaped by politics and piety very different from today's global Church.
Historical Context
Gregory XIII sat on the Chair of Peter during the Renaissance, when popes were among the most powerful patrons of art and architecture in Europe — but also faced corruption scandals, the Protestant Reformation, and the discovery of the New World. Built the Gregorian Chapel in the Vatican.
Pontificate & Key Events
The pontificate (13 May 1572–10 April 1585) centered on governance during the Renaissance papacy. Subject and later the sovereign of the Papal States. Strengthened diplomatic ties with Asian nations. Reformed the calendar(1582).
Papal Acts & Achievements
Gregory XIII left a distinct mark through decisions that historians still debate and Catholics still study. His reign contributed to the continuous apostolic succession now numbering 267 popes. Papal motto: Aperuit et clausit ("Opened and closed").
Key Highlights
- 226th pope of the Catholic Church
- Pontificate: 13 May 1572–10 April 1585
- First pope to bestow the Immaculate Conception as the patron saint of the Philippine Islands through the bull Ilius Fulti Praesido
- Shepherded the Church during the Renaissance papacy
- Successor of St. Peter in the official Catholic list
Legacy in the Catholic Church
Gregory XIII remains pope 226º in the Annuario Pontificio. Read against the Renaissance papacy, his pontificate shows how Providence works through imperfect ministers without abandoning the Barque of Peter.
Why Catholics Study This Pope Today
Studying Gregory XIII helps Catholics see how the Holy Spirit guided the Church through the Renaissance papacy — with human weakness and grace intertwined. Primary sources from this pontificate — bulls, conciliar acts, or encyclicals — reward readers who want depth beyond summaries. Place this pope in context using our chronological list of all 267 popes and the biographies of his immediate predecessor and successor linked below.
Place in the Line of Succession
Gregory XIII followed Pope St. Pius V (225º) in the unbroken line of apostolic succession from St. Peter. Upon his death or resignation, he was succeeded by Pope Sixtus V (227º), who continued the mission of shepherding the universal Church. Explore the full chronological chain in our complete list of all 267 popes, or read the biographies of neighboring pontiffs linked below.