First Vatican Council
- When
- 1869–1870 AD
- Where
- Rome
- Kind
- Council
Defined papal infallibility when the pope teaches ex cathedra, hardening the difference with the eastern and Protestant churches.
Called by Pius IX as the Papal States were being absorbed into a united Italy, the council defined that the pope teaches infallibly when he speaks ex cathedra on faith or morals. The definition is narrower than it is usually taken to be — it binds only formal definitions, of which very few are agreed to qualify — but the minority who opposed it did so largely on the ground that it was inopportune rather than untrue, and a small group left to form the Old Catholic churches. Italian troops entered Rome in September 1870 and the council was suspended, never formally concluded. It hardened the difference with the eastern and Protestant churches at exactly the moment it was defined.
Either side of it
The whole timeline, from the apostolic communities to the present.