Beginning with three synods convened between 264 and 269 in the matter of Paul of Samosata, more than thirty councils were held in Antioch in ancient times. Most of these dealt with phases of the Arian and of the Christological controversies. For example, the Catholic Encyclopedia article on Paul of Samosata[1] states:
The most celebrated took place in the summer of 341 at the dedication of the golden Basilica, and is therefore called in encaeniis (εν εγκαινιοις), in dedicatione. Nearly a hundred bishops were present, all from the Orient, but the bishop of Rome was not represented. The emperor Constantius attended in person.
The council approved three creeds[2]. Whether or not the so-called "fourth formula"[3] is to be ascribed to a continuation of this synod or to a subsequent but distinct assembly of the same year, its aim is like that of the first three; while repudiating certain Arian formulas it avoids the orthodox term "homoousios," fiercely advocated by Athanasius and accepted by the First Council of Nicaea. The somewhat colourless compromise doubtless proceeded from the party of Eusebius of Nicomedia, and proved not unacceptable to the more nearly orthodox members of the synod.
The twenty-five canons adopted regulate the so-called metropolitan constitution of the church. Ecclesiastical power is vested chiefly in the metropolitan (later called archbishop), and the semi-annual provincial synod (cf. Nicaea, canon 5), which he summons and over which he presides. Consequently the powers of country bishops (chorepiscopi) are curtailed, and direct recourse to the emperor is forbidden. The sentence of one judicatory is to be respected by other judicatories of equal rank; re-trial may take place only before that authority to whom appeal regularly lies[4]. Without due invitation, a bishop may not ordain, or in any other way interfere with affairs lying outside his proper territory; nor may he appoint his own successor. Penalties are set on the refusal to celebrate Easter in accordance with the Nicene decree, as well as on leaving a church before the service of the Eucharist is completed.
The numerous objections made by eminent scholars in past centuries to the ascription of these twenty-five canons to the synod in encaeniis have been elaborately stated and probably refuted by Hefele. The canons formed part of the Codex canonum used at Chalcedon in 451 and passed over into the later collections of East and West.
The canons are printed in Greek[5], and translated[6]. The four dogmatic formulas are given by G. Ludwig Hahn[7].