The Christological controversies
Juvenal's episcopate coincided with the decades in which the Church defined how the divine and human are united in the one person of Christ. At Ephesus in 431 he stood with Cyril of Alexandria against the teaching of Nestorius, which was held to divide Christ's natures. Eighteen years later, at the council of 449, he was reckoned among the leaders favorable to Dioscorus of Alexandria.
At Chalcedon in 451 he changed course decisively, affirming the confession of two natures in one Christ, without separation and without confusion, and concurring in the condemnation of Dioscorus. The anchor record summarizes this trajectory as standing for the Orthodox faith at the councils through the stormy years of controversy.