Athanasius I of Alexandria, also called Athanasius the Great, Athanasius the Confessor, or, among Coptic Christians, Athanasius the Apostolic, was a church father and the 20th pope of Alexandria. His intermittent episcopacy spanned 45 years, of which over 17 encompassed five exiles, when he was replaced on the order of four different Roman emperors. Athanasius was a Christian theologian, a Church Father, the chief defender of Trinitarianism against Arianism, and a noted Egyptian Christian leader of the fourth century.
Eunomius, one of the leaders of the extreme or "anomoean" Arians, who are sometimes accordingly called Eunomians, was born at Dacora in Cappadocia or at Corniaspa in Pontus. early in the 4th century.
Paul of Samosata was Bishop of Antioch from 260 to 268 and the originator of the Paulianist heresy named after him. He was a believer in monarchianism, a nontrinitarian doctrine; his teachings reflect adoptionism.
St. Flavian I of Antioch was a bishop or Patriarch of Antioch from 381 until his death.
Saint Meletius was a Christian bishop of Antioch from 360 until his death in 381. He was opposed by a rival bishop named Paulinus and his episcopate was dominated by the schism, usually called the Meletian schism. As a result, he was exiled from Antioch in 361–362, 365–366 and 371–378. One of his last acts was to preside over the First Council of Constantinople in 381.
Demophilus was a bishop of Berea and an archbishop of Constantinople from 370 until he was expelled in 380.
Eusebius of Vercelli was a bishop from Sardinia and is counted a saint. Along with Athanasius, he affirmed the divinity of Jesus against Arianism.
Hosius of Corduba, also known as Osius or Ossius, was a bishop of Corduba and an important and prominent advocate for Homoousion Christianity in the Arian controversy that divided the early Christianity.
Acacius of Caesarea was a Christian bishop probably originating from Syria; Acacius was the pupil and biographer of Eusebius and his successor on the see of Caesarea Palestina. Acacius is remembered chiefly for his bitter opposition to Cyril of Jerusalem and for the part he was afterwards enabled to play in the more acute stages of the Arian controversy. The Acacian theological movement is named after him. In the twenty-first oration of St. Gregory Nazianzen, the author speaks of Acacius as being "the tongue of the Arians".
Semi-Arianism was a position regarding the relationship between God the Father and the Son of God, adopted by some 4th-century Christians. Though the doctrine modified the teachings of Arianism, it still rejected the doctrine that Father, Son, and Holy Spirit are co-eternal, and of the same substance, or consubstantial, and was therefore considered to be heretical by many contemporary Christians.
Marcellus of Ancyra was a Bishop of Ancyra and one of the bishops present at the Council of Ancyra and the First Council of Nicaea. He was a strong opponent of Arianism, but was accused of adopting the opposite extreme of modified Sabellianism. He was condemned by a council of his enemies and expelled from his see, though he was able to return there to live quietly with a small congregation in the last years of his life. He is also said to have destroyed the temple of Zeus Belos at Apamea.
George was the bishop of Laodicea in Syria from 335 until his deposition in 347. He took part in the Trinitarian controversies of the fourth century. At first an ardent admirer of the teaching of Arius and associated with Eusebius of Nicomedia, he subsequently became a semi-Arian, but seems ultimately to have united with the Anomoeans, whose uncompromising opponent he had once been, and to have died professing their tenets.
Aëtius of Antioch, surnamed "the Atheist" by his trinitarian enemies, founder of Anomoeanism, was a native of Coele-Syria.
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 states:
It must be regarded as certain that the council which condemned Paul rejected the term homoousios; but naturally only in a false sense used by Paul; not, it seems because he meant by it a unity of Hypostasis in the Trinity, but because he intended by it a common substance out of which both Father and Son proceeded, or which it divided between them, — so St. Basil and St. Athanasius; but the question is not clear. The objectors to the Nicene doctrine in the fourth century made copious use of this disapproval of the Nicene word by a famous council.
The Council of Seleucia was an early Christian church synod at Seleucia Isauria.
The Second Council of Ephesus was a Christological church synod in 449 AD convened by Emperor Theodosius II under the presidency of Pope Dioscorus I of Alexandria. It was intended to be an ecumenical council, and it is accepted as such by the miaphysite churches but was rejected by Chalcedonian Christians. It was explicitly repudiated by the next council, the Council of Chalcedon of 451, recognised as the fourth ecumenical council by Chalcedonian Christians, and it was named the Latrocinium by Pope Leo I; the Chalcedonian churches, particularly the Roman Catholic and Eastern Orthodox communions, continue to accept this designation, while the Oriental Orthodox repudiate it.
Alexander of Jerusalem was a third century bishop who is venerated as a martyr and saint by the Eastern Orthodox Church, Oriental Orthodox churches, and the Roman Catholic Church. He died during the persecution of Emperor Decius.
The Arian controversy was a series of Christian disputes about the nature of Christ that began with a dispute between Arius and Athanasius of Alexandria, two Christian theologians from Alexandria, Egypt. The most important of these controversies concerned the relationship between the substance of God the Father and the substance of His Son.
The Pneumatomachi, also known as Macedonians or Semi-Arians in Constantinople and the Tropici in Alexandria, were an anti-Nicene Creed sect which flourished in the regions adjacent to the Hellespont during the latter half of the fourth, and the beginning of the fifth centuries. They denied the godhood of the Holy Ghost, hence the Greek name Pneumatomachi or 'Combators against the Spirit'.
The Councils of Alexandria started in 231 AD as a council of bishops and priests met at Alexandria, Egypt, called by Bishop Demetrius for the purpose of declaring Origen of Alexandria unworthy of the office of teacher, and of excommunicating him.
