Written by Guide Catholic
Pope Celestine II (165º): Biography, Pontificate & Legacy
Pontificate: 26 September 1143–8 March 1144 · Origin: Città di Castello, Sacro Roman Empire · Birth name: Coelestinus Secundus
Celestine II was the 165th pope of the Catholic Church, reigning 26 September 1143–8 March 1144 during the high Middle Ages. Subject and later the sovereign of the Papal States.
Who Was Pope Celestine II?
Pope Celestine II — 165º in the Catholic list — reigned 26 September 1143–8 March 1144 during the high Middle Ages. Subject and later the sovereign of the Papal States. This Guide Catholic profile gathers background, major acts, and legacy so you can read Celestine II beside neighboring pontiffs.
Early Life & Background
Before election he was known as Guido Guelfuccio di Castello. Born circa 1085 Città di Castello, Papal States, he entered a world shaped by politics and piety very different from today's global Church.
Historical Context
Celestine II (#undefined) led during crusades, monastic reform, and cathedral culture — and during sharp contests between popes and emperors over authority in Christendom.
Pontificate & Key Events
The pontificate (26 September 1143–8 March 1144) centered on governance during the high Middle Ages.
Papal Acts & Achievements
Acts associated with Celestine II (#165, 26 September 1143–8 March 1144) 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.
Key Highlights
- 165th pope of the Catholic Church
- Pontificate: 26 September 1143–8 March 1144
- Shepherded the Church during the high Middle Ages
- Successor of St. Peter in the official Catholic list
Legacy in the Catholic Church
Celestine II remains pope 165º in the Annuario Pontificio. Set against the high Middle Ages, Celestine II's choices show both the limits of any one pontiff and the continuity of the office he held.
Why Catholics Study This Pope Today
Reading Celestine II as pope 165º (26 September 1143–8 March 1144) is a way to study how Rome answered the crises of the high Middle Ages. Begin with this documented note: Subject and later the sovereign of the Papal States. Compare Celestine II with the biographies of his predecessor and successor linked below to see reform, rupture, or quiet continuity.
Place in the Line of Succession
Celestine II followed Pope Innocent II (164º, 14 February 1130–24 September 1143) after a transition shaped by the politics and piety of their shared century. He was followed by Pope Lucius II (166º, 12 March 1144–15 February 1145), 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.