A zealous hierarch, he took part in two Ecumenical Councils: the Third in Ephesus, which rebuked the doctrines of Nestorius; and the Fourth at Chalcedon, which rebuked the teachings of Eutyches and Dioscoros that Christ has only one nature, divine but not human. Following these councils, he returned to his see in Jerusalem. But through the plotting of Dioscoros' allies, he was driven from his throne and Theodosius, a monophysite, was installed in his place. The Empress Eudocia, widow of the Emperor Theodosius the younger, initially supported the heretics. But, unsure of the true Orthodox doctrine, she went to inquire of St Symeon the Stylite, who denounced the monophysite doctrine and told the Empress to do all that she could to uphold the teaching of the Councils. Obeying him, she condemned the false Patriarch Theodosius and prevailed on the Emperor Marcian to have him deposed. Thus St Juvenal was at last restored to his patriarchal throne. He served the Church in peace, for a total of thirty-eight years, and reposed at a great old age.