On the Origin of Papal Primacy

Council of Chalcedon 451

[T]he Fathers rightly granted privileges to the throne of old Rome, because it was the royal city. (Canon 28)

St. Nicholas Cabasilas ca. 1323-1391

[T]he pope indeed has two privileges: he is the bishop of Rome…and he is the first among the bishops. From Peter he has received the Roman episcopacy; as to the primacy, he received it much later from the blessed Fathers and the pious Emperors, for it was just that ecclesiastical affairs be accomplished in order. (De Primatu Papae, PG 149, 701 CD)