Chalcedon, Council of, fourth ecumenical council, convened in 451 by Pulcheria and Marcian, empress and emperor of the East, to settle the scandal of the Robber Synod and to discuss Eutychianism (see Eutyches). It deposed the principals in the Robber Synod and destroyed the Eutychian party. Its great work, however, was its Definition regarding the nature and person of Jesus. Based upon the formulation given by Pope St. Leo I in his famous Tome to Flavian, it declared that, contrary to the view taken by Eutychianism (see Eutyches) and Monophysitism, the second Person of the Trinity has two distinct natures—one divine and one human. It was also proclaimed that these two natures exist inseparably in one person. This difference was a major factor in the Monophysite schism that divided the East for centuries. The council produced 28 disciplinary canons important for canon law in both the East and West. However, the Roman Catholic Church did not admit the 28th canon, which made the patriarch of Constantinople second only to the pope in Rome in precedence, until the Fourth Lateran Council (1215).

Chalcedon, ancient Greek city of Asia Minor, on the Bosporus. It was founded by Megara on the shore opposite Byzantium in 685 B.C. Taken by the Persians and recovered by the Greeks, it was later a possession of the kings of Bithynia, from whom it passed (A.D. 74) to Rome. The Council of Chalcedon was held there in A.D. 451. The site is in the suburbs of Istanbul.

(451) Fourth ecumenical council of the Christian Church, held in Chalcedon (modern Kadiköy, Tur.). Called by the emperor Marcian, it approved the creeds of Nicaea (325) and Constantinople (381; later known as the Nicene Creed). It also approved the Tome of Pope Leo I confirming the two distinct natures in Christ and rejecting the Monophysite heresy. The council then explained these doctrines in its own confession of faith. The council disciplined clergy and declared Jerusalem and Constantinople patriarchates.

Learn more about Chalcedon, Council of with a free trial on Britannica.com.

(451) Fourth ecumenical council of the Christian Church, held in Chalcedon (modern Kadiköy, Tur.). Called by the emperor Marcian, it approved the creeds of Nicaea (325) and Constantinople (381; later known as the Nicene Creed). It also approved the Tome of Pope Leo I confirming the two distinct natures in Christ and rejecting the Monophysite heresy. The council then explained these doctrines in its own confession of faith. The council disciplined clergy and declared Jerusalem and Constantinople patriarchates.

Learn more about Chalcedon, Council of with a free trial on Britannica.com.