An apostolic see is a see that was founded by an Apostle. The number of sees and their names differed from century to century. In the fourth century, Rome, Alexandria, Antioch, and Ephesus were considered the four apostolic sees. However, with the foundation of Constantinople as a capital, the emperors started to assert their capital as an apostolic see, especially in the Council of Constantinople in 381 a.d. The relics of St. Andrew were later discovered in order to justify their assertion. From the beginning of the fifth century, the other apostolic sees opposed this innovation.
This can be detected in the attitude of the Egyptian popes such as Theophilus and Cyril toward the patriarchs of Constantinople, such as John Chrysostom and Nestorius (the heretic).
The Council of Chalcedon in 451 a.d. declared the famous Canon 28 (rejected for a long time by Rome), which considered the See of Constantinople as the second see after Rome, for it was the “New Rome.” Through the machinations of its bishop, Juvenal, Jerusalem also became a patriarchate at the same council. Later, Moscow took the title of “New Rome.”
In the Coptic tradition, the four apostolic sees are Rome, Alexandria, Antioch, and Ephesus, as mentioned in a Coptic hymn in honor of Julius of Rome, though the manuscripts erroneously attribute the hymn to his namesake, Julius of Akfahs. In the History of the Patriarchs of the Egyptian church, there is a quotation from a work by Severus of Antioch mentioning the four parts of the garment of Christ as the four (apostolic) seats that exist in the world.