Pope Gregory XIII (226º): Vatican I & Dogma & Gregorian Calendar — Complete Guide

Who Was Pope Gregory XIII?

Gregory XIII holds the 226º place among Roman pontiffs, with a recorded reign of 13 May 1572–10 April 1585 inside the Renaissance papacy. Search interest often clusters around Vatican I & Dogma and Gregorian Calendar. Subject and later the sovereign of the Papal States. What follows is a structured biography — early life, context, acts, and succession — written for Catholics who want Gregory XIII in context.

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 (#undefined) sat on Peter's chair amid artistic patronage, political intrigue, Reformation shocks, and the widening world of the Americas. 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. Strengthened diplomatic ties with Asian nations. Reformed the calendar(1582).

Papal Acts & Achievements

Acts associated with Gregory XIII (#226, 13 May 1572–10 April 1585) still draw historians and Catholics who want more than a one-line summary. His reign remains a link in the succession now counted at 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. Set against the Renaissance papacy, Gregory XIII's choices show both the limits of any one pontiff and the continuity of the office he held.

Why Catholics Study This Pope Today

Place Gregory XIII on your mental map: 226º successor of Peter, reigning 13 May 1572–10 April 1585, formed by the Renaissance papacy. Start with the concrete record: Built the Gregorian Chapel in the Vatican. First pope to bestow the Immaculate Conception as the patron saint of the Philippine Islands through the bull Ilius Fulti Praesido (1579). Where bulls, conciliar acts, or encyclicals survive from this reign, they repay readers who want primary sources rather than summaries alone. Then step back to the full list of 267 popes to see where Gregory XIII sits between crisis and consolidation.

Place in the Line of Succession

Gregory XIII followed Pope St. Pius V (225º, 7 January 1566–1 May 1572) after a transition shaped by the politics and piety of their shared century. He was followed by Pope Sixtus V (227º, 24 April 1585–27 August 1590), whose biography continues the chain on Guide Catholic. For the full chronological map, see our complete list of all 267 popes — then read neighboring biographies for contrast, not only continuity.