# Pope Leo IX - Pope

URL: https://christianity-history.com/popes/pope-leo-ix
Pontificate: 12 February 1049 – 19 April 1054
Number in the papal list: 152
Born-Died: 1002 - 1054
Papal era: Gregorian Reform
Wikipedia: https://en.wikipedia.org/wiki/Pope_Leo_IX

Subject of the Duchy of Swabia. In 1054, the mutual excommunications of Leo IX's legate, cardinal Humbert of Silva Candida, and Patriarch Michael I Cerularius of Constantinople started the East–West Schism.

## Succession
- Previous in list: [Pope Damasus II](https://christianity-history.com/popes/pope-damasus-ii)
- Next in list: [Pope Victor II](https://christianity-history.com/popes/pope-victor-ii)

## Timeline events during this pontificate
- 1049 - [Gregorian Reform begins](https://christianity-history.com/timeline/1049-gregorian-reform-begins)
- 1054 - [East-West Schism](https://christianity-history.com/timeline/1054-east-west-schism)