Council of Chalcedon
The Council of Chalcedon took place in 451 A.D. It is the fourth of the first seven Ecumenical Councils in Christianity, and is therefore recognized as infallible in its dogmatic definitions by the Roman Catholic and Eastern Orthodox churches. It set forth the Chalcedonian Creed, which describes the full humanity and full divinity of Jesus Christ, the second person of the Holy Trinity. Ecumenical councils after the seventh are recognized as infallible only by Roman Catholics.