Chalcedon, an ancient town of Asia Minor, on the Bosporus, opposite Constantinople, and near the modern town of Scutari. It was founded by a colony from Megara about 680 B. 0., who were ridiculed as blind by the ancients because they settled here and overlooked the admirable site directly opposite, where Byzantium was founded about 20 years later. For this reason Chalcedon was often called the city of the blind. About 506, in the reign of Darius, it was taken by the Persians, then by the Athenians and Lacedaemonians, and after a period of independence fell under the dominion of the kings of Bithynia. The Romans got possession of it in 74 B. C. Its walls were destroyed by Valens, and it is now but a poor village called Kadi-kei. - In ecclesiastical history Chalcedon is celebrated as the seat of the fourth oecumenical council, convoked in 451, at the request of the patriarch of Constantinople, Flavian, by the emperor Marcian, to condemn the heresy of Eutyches concerning the two natures of Christ, and to counteract the effect of the unauthorized assembly held at Ephesus in 449, and generally stigmatized as the robber synod. The council met on Oct. 8, and 630 bishops, chiefly from the East, were present. Pope Leo I. presided by his legates.

The creeds of Nice and Constantinople were adopted as the rule of faith; and after a prolonged discussion the latrocinium of the Ephesian assembly, as well as the doctrines of Eutyches and Dioscorus, in favor of which that synod had pronounced, was condemned. The bishops professed their belief in the existence of two natures in Christ, and declared the Virgin Mary truly the mother of God, directing their decree against both Nestorian and Monophysite doctrines. Fifteen sessions were held, in which 30 disciplinary canons were promulgated, among which was the celebrated decree, opposed by the Roman legates, which made the see of Constantinople equal in privileges and jurisdiction, and next in rank, to that of Rome. It was also ordered that no bishop should take money for ordination, that no ecclesiastic should undertake the administration of the temporal matters of the church or of widows and orphans, forsake the church for any other office, go before a lay tribunal, or hold more than one benefice. Bishops were forbidden to divide their provinces, and were given control over the clergy in monasteries.

Deaconesses were forbidden to be appointed under the age of 40. Differences were adjusted between the sees of An-tioch and Jerusalem, Nicomedia and Nice; and Theodoret, deposed in consequence of a decree of the assembly of Ephesus, was restored to his bishopric. These decrees were confirmed by Leo, with the exception of the one relating to the see of Constantinople; and throughout the Latin church the council of Chalcedon has always been venerated.