The Council of Chalcedon

The Road to Chalcedon

The bishops at Ephesus (431) had rejected any division of Christ into two persons. But some who opposed Nestorius swung to the other extreme. In 448 a synod of bishops in Constantinople condemned Eutyches, who taught that after the union Christ had only one nature.

Leo, bishop of Rome, whose claim to rule the western bishops Emperor Valentinian III had backed by edict in 445, sent a careful letter, the Tome, explaining that each nature keeps its own properties in the one person of Christ. But a second council at Ephesus in 449 restored Eutyches by force. Leo called it a robber synod. After Emperor Theodosius II died in 450, his successor Marcian summoned a new council, which met at Chalcedon in October 451.