John of Cappadocia, surnamed Cappadox or the Cappadocian (Greek: Ἰωάννης ὁ Καππαδόκης; died February 520), was patriarch of Constantinople in 518–520, during the reign of Byzantine emperor Anastasius I Dicorus after an enforced condemnation of the Council of Chalcedon.
His short patriarchate is memorable for the celebrated Acclamations of Constantinople, and the reunion of East and West after a schism of 34 years.
On 15 July, the new emperor entered the cathedral, and the patriarch, accompanied by twelve prelates, was making his way through the throngs that crowded every corner.
The procession passed into the inclosure, but the excited congregation went on shouting outside the gates of the choir in similar strains: "You shall not come out unless you anathematise Severus",[1] referring to the heretical patriarch of Antioch.
[1] The people were determined to have a more formal decision, and continued shouting for several hours, mingling with their former cries such as these: "Fix a day for a festival in honour of Chalcedon!"
This extemporaneous and intimidated council then carried a decree by acclamation: "It is plain to all that Severus in separating himself from this church condemned himself.
Again as the patriarch made his processional entrance and approached the pulpit clamours arose: "Restore the relics of Macedonius II of Constantinople to the church!
Then the multitude chanted for more than an hour, "Blessed be the Lord God of Israel, for He hath visited and redeemed His people!".
[1] The choir assembled on the raised platform, and, turning eastwards, sang the Trisagion, the whole people listening in silence.
When the moment arrived for the recitation of the names of the defunct bishops from the diptychs, the multitude closed in silence about the holy table; and when the deacon had read the new insertions, a mighty shout arose, "Glory be to Thee, O Lord!".
His letters were accompanied by orders from Justin to restore all who had been banished by Anastasius and to inscribe the Council of Chalcedon in the diptychs.
The emperor Justin wrote to the pope a fortnight after the scene of the acclamations, begging him to further the desires of the patriarch John for the reunion of the churches.
A deputation was sent to Constantinople with instructions that Acacius was to be anathematised by name, but that Euphemius and Macedonius II might be passed over in silence.
The emperor sent an account of the proceedings throughout the provinces and the ambassadors forwarded their report to Rome, saying that there only remained the negotiations with the Patriarch of Antioch.
John wrote to Pope Hormisdas to congratulate him on the great work, and to offer him the credit of its success.