# Council of Chalcedon (451)

URL: https://christianity-history.com/timeline/451-council-of-chalcedon
Location: Chalcedon, Bithynia
Themes: Council

The fourth ecumenical council defines Christ as one person in two natures; its rejection leads to the separation of the Oriental Orthodox churches. At this point in the timeline (451), the Bishop of Rome was Pope Leo I "the Great" (29 September 440 – 10 November 461).

## Why it matters
Chalcedon produced the first lasting division among Christian churches.

Pope at the time: [Pope Leo I "the Great"](https://christianity-history.com/popes/pope-leo-i-the-great)

## Sources
- [Wikipedia — Council of Chalcedon](https://en.wikipedia.org/wiki/Council_of_Chalcedon)
- [Encyclopaedia Britannica topic lookup — Council of Chalcedon](https://www.britannica.com/search?query=Council+of+Chalcedon)
- [Wikipedia — Age Of Councils (period overview)](https://en.wikipedia.org/wiki/First_seven_ecumenical_councils)