# First Vatican Council defines papal infallibility (1870)

URL: https://christianity-history.com/timeline/1870-first-vatican-council-defines-papal-infallibility
Location: Rome
Themes: Council

Vatican I's Pastor aeternus defines papal primacy and infallibility. At this point in the timeline (18 July 1870), the Bishop of Rome was Pope Pius IX (16 June 1846 – 7 February 1878).

## Why it matters
First Vatican Council defines papal infallibility mattered because its decisions defined doctrine, discipline or church order for generations of Christians.

Pope at the time: [Pope Pius IX](https://christianity-history.com/popes/pope-pius-ix)

## Sources
- [Wikipedia — First Vatican Council](https://en.wikipedia.org/wiki/First_Vatican_Council)
- [Encyclopaedia Britannica topic lookup — First Vatican Council defines papal infallibility](https://www.britannica.com/search?query=First+Vatican+Council+defines+papal+infallibility)
- [Wikipedia — Modern Era (period overview)](https://en.wikipedia.org/wiki/Christianity_in_the_20th_century)