Athanasius of Alexandria in the context of "List of Roman emperors"

John Chrysostom (/ˈkrɪsəstəm, krɪˈsɒstəm/; Greek: Ἰωάννης ὁ Χρυσόστομος, Latin: Ioannes Chrysostomus; c. 347 – 14 September 407) was an important Church Father who served as Archbishop of Constantinople. He is known for his preaching and public speaking, his denunciation of abuse of authority by both ecclesiastical and political leaders, his Divine Liturgy of Saint John Chrysostom, and his ascetic sensibilities. He was also the author of Adversus Judaeos and was strongly against Judaism. The epithet Χρυσόστομος (Chrysostomos, anglicized as Chrysostom) means "golden-mouthed" in Greek and denotes his celebrated eloquence. Chrysostom was among the most prolific authors in the early Christian Church.

He is honored as a saint in the Eastern Orthodox, Oriental Orthodox, Catholic, Anglican, and Lutheran churches, as well as in some others. The Eastern Orthodox, together with the Byzantine Catholics, hold him in special regard as one of the Three Holy Hierarchs (alongside Basil of Caesarea and Gregory of Nazianzus). Along with them and Athanasius of Alexandria he is also regarded as one of the four Great Greek Church Fathers. The feast days of John Chrysostom in the Eastern Orthodox Church are 14 September, 13 November and 27 January. In the Catholic Church, he is recognised as a Doctor of the Church. Because the date of his death is occupied by the feast of the Exaltation of the Holy Cross (14 September), the General Roman Calendar celebrates him since 1970 on the previous day, 13 September; from the 13th century to 1969 it did so on 27 January, the anniversary of the translation of his body to Constantinople. Of other Western churches, including Anglican provinces and Lutheran churches, some commemorate him on 13 September, others on 27 January. John Chrysostom is honored on the calendars of the Church of England and the Episcopal Church on 13 September. The Coptic Church also recognizes him as a saint (with feast days on 16 Thout and 17 Hathor).

Pope Julius I was the bishop of Rome from 6 February 337 to his death on 12 April 352. He was appealed to by Athanasius when the latter was deposed from his position as patriarch by Arian bishops, Julius then supported Athanasius and condemned his deposition as unjust. He was notable for asserting the authority of the pope over the Arian Eastern bishops, as well as being attributed with the setting of December 25 as the official birthdate of Jesus.

Various early Christian writers wrote gospels and other books, some of which were canonized as the New Testament canon developed. The Apostolic Fathers were prominent writers who are traditionally understood to have met and learned from Jesus's personal disciples. The Church Fathers are later writers with no direct connection to the disciples (other than the claim to apostolic succession). Early Christian apologists tried to defend Christianity against its critics, especially the Ancient Greek and Roman philosophers. Dates given, if not otherwise specified, are of their writings or bishopric, not of their lives.

• Paul of Tarsus, "Apostle to the Gentiles", earliest New Testament author 45~65
• Four Evangelists, traditionally identified as the authors of the canonical gospels 60~125
• Ignatius, bishop of Antioch, apostolic father 68~107
• Marcion of Sinope, evangelist and theologian, founder of Marcionism, published the first known canon of the New Testament, 85~160
• Clement of Rome, bishop of Rome, apostolic father 88~101
• Papias, bishop of Hierapolis, apostolic father 110~130
• Polycarp of Smyrna, bishop of Smyrna, apostolic father 110~160
• Aristides of Athens, apologist ~120
• Justin Martyr, church father ~165
• Melito of Sardis, bishop of Sardis, ~180
• Irenaeus, bishop of Lyon, disciple of Polycarp, apologist 180~202
• Origen of Alexandria, 185~254, Neoplatonist, controversial during his lifetime, posthumously condemned at the Second Council of Constantinople in 553
• Tatian, pupil of Justin Martyr, ascetic theologian ~185
• Athenagoras of Athens, philosopher, apologist ~190
• Polycrates, bishop of Ephesus, excommunicated by Victor I of Rome over the Easter controversy ~196
• Montanus, self-proclaimed prophet and founder of Montanism, last quarter of 2nd century CE
• Tertullian, church father, apologist, first Christian writer in Latin, later a Montanist 197~230
• Hippolytus, church father, sometimes termed the first Antipope, reconciled with the church and died a martyr 217~236
• Cyprian, bishop of Carthage, martyr 218~258
• Clement of Alexandria, church father, Bishop of Alexandria ~220
• Novatian, a rigorist and Antipope in 251
• Dionysius, patriarch of Alexandria, pope of the Coptic Orthodox Church 248~264
• Paul of Samosata, bishop of Antioch, adoptionist, condemned at 269 Council of Antioch
• Athanasius of Alexandria, c. 297~373, patriarch of Alexandria, defender of the Trinitarian doctrine
• Donatus Magnus, bishop of Carthage, (+355), leader of the Donatists from 313
• Lactantius, apologist ~317
• Arnobius, apologist ~330
• Eusebius, wrote History of the Church ~325
• Augustine of Hippo, 354-430, Latin church father, wrote Confessions and City of God

Arius (/əˈraɪəs, ˈɛəri-/; Koine Greek: Ἄρειος, romanized: Áreios; 250 or 256 – 336) was a Cyrenaic presbyter and ascetic. He has been regarded as the founder of Arianism, which holds that Jesus Christ was not coeternal with God the Father, but was rather created by God the Father. Arian theology and its doctrine regarding the nature of the Godhead showed a belief in radical subordinationism, a view notably disputed by 4th century figures such as Athanasius of Alexandria.

Constantine the Great's formal decriminalization of Christianity into the Roman Empire entailed the convention of ecumenical councils to remove theological divisions between opposing sects within the Church. Arius's theology was a prominent topic at the First Council of Nicaea, where Arianism was condemned in favor of Homoousian conceptions of God and Jesus. Opposition to Arianism remains embodied in the Nicene Creed, described as "a deliberately anti-Arian document." Nevertheless, despite concerted opposition, Arian churches persisted for centuries throughout Europe (especially in various Germanic kingdoms), the Middle East, and North Africa. They were suppressed by military conquest or by voluntary royal conversion between the fifth and seventh centuries.

Flavius Julius Constans (c. 323 – 350), also called Constans I, was Roman emperor from 337 to 350. He held the imperial rank of caesar from 333, and was the youngest son of Constantine the Great.

After his father's death, he was made augustus alongside his brothers in September 337. Constans was given the administration of the praetorian prefectures of Italy, Illyricum, and Africa. He defeated the Sarmatians in a campaign shortly afterwards. Quarrels over the sharing of power led to a civil war with his eldest brother and co-emperor Constantine II, who invaded Italy in 340 and was killed in battle by Constans's forces near Aquileia. Constans gained from him the praetorian prefecture of Gaul. Thereafter there were tensions with his remaining brother and co-augustus Constantius II (r. 337–361), including over the exiled bishop Athanasius of Alexandria, who in turn eulogized Constans as "the most pious Augustus... of blessed and everlasting memory." In the following years he campaigned against the Franks, and in 343 he visited Roman Britain, the last legitimate emperor to do so until Manuel II in 1400, more than a thousand years later.

The Athanasian Creed—also called the Quicunque Vult (or Quicumque Vult), which is both its Latin name and its opening words, meaning "Whosoever wishes"—is a Christian statement of belief focused on Trinitarian doctrine and Christology. Used by Christian churches since the early sixth century, it was the first creed to explicitly state the equality of the three hypostases of the Trinity. It differs from the Nicene-Constantinopolitan Creed and the Apostles' Creed in that it includes anathemas condemning those who disagree with its statements, as does the original Nicene Creed.

Widely accepted in Western Christianity, including by the Roman Catholic Church, Lutheran Churches (it is part of the Lutheran confessions set out in the Book of Concord), Anglican Churches, Reformed Churches, and ancient liturgical churches, the Athanasian Creed has been used in public worship less frequently, with exception of Trinity Sunday. However, part of it can be found as an "Authorized Affirmation of Faith" in the main volume of the Common Worship liturgy of the Church of England published in 2000. Despite falling out of liturgical use, the creed's influence on current Protestant understanding of trinitarian doctrine is clear.

Meletius of Antioch (Greek: Μελέτιος, Meletios) was a Christian patriarch of Antioch from 360 until his death in 381. He was opposed by a rival bishop named Paulinus II of Antioch 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.

There are contrasting views about his theological position: on the one hand, he was exiled three times under Arian emperors; on the other, he was strongly opposed by those faithful to the memory of the staunchly pro-Nicene Eustathius of Antioch, whom the synod of Melitene deposed for his Homoousianism, which they considered a heresy, and by Saint Athanasius of Alexandria, a firm opponent of Arianism.

Achillas was the 18th Patriarch of Alexandria, reigning from 312 to 313.

He was born in Alexandria, Egypt, and was renowned for his knowledge and piety; this was why Pope Theonas had ordained him priest and appointed him head of the Catechetical School of Alexandria upon the departure of Pierius. He was apparently very highly thought of for his work in Greek philosophy and theological science, as Pope Athanasius later described him by the honorific "Achillas the Great".

The Desert Fathers were early Christian hermits and ascetics, who lived primarily in the Wadi El Natrun, then known as Skete, in Roman Egypt, beginning around the third century. The Sayings of the Desert Fathers is a collection of saying and other texts attributed to desert monks and nuns from this era.

The first Desert Father was Paul of Thebes. The most well-known Anthony the Great, who moved to the desert in 270–271 and became known as both the father and founder of desert monasticism. By the time Anthony had died in 356, thousands of monks and nuns had been drawn to live in the desert following Anthony's example, leading his biographer, Athanasius of Alexandria, to write that "the desert had become a city." The Desert Fathers significantly influenced the development of Christianity.