Doctor of the Church (Latin: doctor "teacher"), also referred to as Doctor of the Universal Church (Latin: Doctor Ecclesiae Universalis), is a title given by the Catholic Church to saints recognized as having made a significant contribution to theology or doctrine through their research, study, or writing. 
As of 2023 [update] , the Catholic Church has named 37 Doctors of the Church. Of these, the 18 who died before the Great Schism of 1054 are also held in high esteem by the Eastern Orthodox Church, although it does not use the formal title "Doctor of the Church".
Among the 37 recognised Doctors, 28 are from the West and nine from the East; four are women and thirty-three are men; one abbess, three nuns, one tertiary associated with a religious order; 19 bishops, twelve priests, one deacon; 27 from Europe, three from Africa, and seven from Asia. More Doctors (twelve) lived in the fourth century than any other; eminent Christian writers of the first, second, and third centuries are usually referred to as the Ante-Nicene Fathers. The shortest period between death and nomination was that of Alphonsus Liguori, who died in 1787 and was named a Doctor in 1871 – a period of 84 years; the longest was that of Irenaeus, which took more than eighteen centuries.
Some other churches have similar categories with various names.
In the Western church four outstanding "Fathers of the Church" attained this honour in the early Middle Ages: Gregory the Great, Ambrose, Augustine of Hippo, and Jerome. The "four Doctors" became a commonplace notion among scholastic theologians, and a decree of Boniface VIII (1298) ordering their feasts to be kept as doubles throughout the Latin Church is contained in his sixth book of Decretals (cap. "Gloriosus", de relique. et vener. sanctorum, in Sexto, III, 22). 
In the Byzantine Church, three Doctors were pre-eminent: John Chrysostom, Basil the Great, and Gregory of Nazianzus. The feasts of these three saints were made obligatory throughout the Eastern Empire by Leo VI the Wise. A common feast was later instituted in their honour on 30 January, called "the feast of the three Hierarchs". In the Menaea for that day it is related that the three Doctors appeared in a dream to John Mauropous, Bishop of Euchaita, and commanded him to institute a festival in their honour, in order to put a stop to the rivalries of their votaries and panegyrists. 
This was under Alexius Comnenus (1081–1118; see "Acta SS.", 14 June, under St. Basil, c. xxxviii). But sermons for the feast are attributed in manuscripts to Cosmas Vestitor, who flourished in the tenth century. The three are as common in Eastern art as the four are in Western. Durandus (i, 3) remarks that Doctors should be represented with books in their hands. In the West analogy led to the veneration of four Eastern Doctors, Athanasius of Alexandria being added to the three hierarchs. 
The details of the title, Doctor of the Church, vary from one autonomous ritual church to another.
In the Latin Church, the four Latin Doctors "had already long been recognized" in the liturgy when the four Great Doctors of the Eastern Church, John Chrysostom, Basil the Great, Gregory of Nazianzus, and Athanasius of Alexandria were recognized in 1568 by Pope Pius V.
To these names others have subsequently been added. The requisite conditions are enumerated as three: eminens doctrina, insignis vitae sanctitas, Ecclesiae declaratio (i.e. eminent learning, a high degree of sanctity, and proclamation by the church). Benedict XIV explains the third as a declaration by the supreme pontiff or by a general council.[ citation needed ] But though general councils have acclaimed the writings of certain Doctors, no council has actually conferred the title of Doctor of the Church. The procedure involved extending to the Catholic Church the use of the Divine Office and Mass of the saint in which the title of doctor is applied to him.
The decree is issued by the Congregation for the Causes of the Saints and approved by the pope, after a careful examination, if necessary, of the saint's writings. It is not in any way an ex cathedra decision, nor does it even amount to a declaration that no error is to be found in the teaching of the Doctor. It is, indeed, well known that the very greatest of them are not wholly immune from error. Formally no martyrs were on the list, since the Office and the Mass had been for Confessors. Hence, as Benedict XIV pointed out during his pontificate, Ignatius of Antioch, Irenaeus of Lyons, and Cyprian of Carthage were not called Doctors of the Church.[ citation needed ] This changed in 2022 when Pope Francis declared Irenaeus of Lyons the first martyred Doctor.
The Doctors' works vary greatly in subject and form. Augustine of Hippo was one of the most prolific writers in Christian antiquity and wrote in almost every genre. Some, such as Pope Gregory the Great and Ambrose of Milan, were prominent writers of letters. Pope Leo the Great, Pope Gregory the Great, Peter Chrysologus, Bernard of Clairvaux, Anthony of Padua and Lawrence of Brindisi left many homilies. Catherine of Siena, Teresa of Ávila, John of the Cross and Thérèse de Lisieux wrote works of mystical theology. Athanasius of Alexandria and Robert Bellarmine defended the church against heresy. Bede the Venerable wrote biblical commentaries and theological treatises. Systematic theologians include the Scholastic philosophers Anselm of Canterbury, Albert the Great, and Thomas Aquinas.
In the 1920 encyclical Spiritus Paraclitus, Pope Benedict XV refers to Jerome as the church's "Greatest Doctor". 
Until 1970, no woman had been named a Doctor of the Church. Since then four additions to the list have been women: Teresa of Ávila (also known as Saint Teresa of Jesus) and Catherine of Siena by Pope Paul VI; Thérèse de Lisieux  (also known as Saint Therese of the Child Jesus and of the Holy Face), "the Little Flower" by Pope John Paul II; and Hildegard of Bingen by Benedict XVI. Teresa and Thérèse were both Discalced Carmelites, Catherine was a Dominican, and Hildegard was a Benedictine nun.
Traditionally, in the Liturgy, the Office of Doctors was distinguished from that of Confessors by two changes: the Gospel reading Vos estis sal terrae ("You are the salt of the earth"), Matthew 5:13–19, and the eighth Respond at Matins, from Ecclesiasticus 15:5, In medio Ecclesiae aperuit os ejus, * Et implevit eum Deus spiritu sapientiae et intellectus. * Jucunditatem et exsultationem thesaurizavit super eum. ("In the midst of the Church he opened his mouth, * And God filled him with the spirit of wisdom and understanding. * He heaped upon him a treasure of joy and gladness.") The Nicene Creed was also recited at Mass, which is normally not said except on Sundays and the highest-ranking feast days. The 1962 revisions to the Missal dropped the Creed from feasts of Doctors and abolished the title and the Common of Confessors, instituting a distinct Common of Doctors.
On 20 August 2011, Pope Benedict XVI announced that he would soon declare John of Ávila a Doctor of the Church.  Although no official announcement was given, it was reported in December 2011 that Pope Benedict intended to declare Hildegard of Bingen as a Doctor of the Church despite her not yet having been formally canonized by the papacy.  Hildegard of Bingen was officially declared to be a saint of the Catholic Church by Pope Benedict XVI on 10 May 2012, clearing the way for her to be named a Doctor of the Church.  Pope Benedict formally declared John of Ávila and Hildegard of Bingen to be Doctors of the Church on 7 October 2012. 
Pope Francis declared the 10th century Armenian monk Gregory of Narek to be the 36th Doctor of the Church on 21 February 2015.  The decision was somewhat controversial. According to critics of Pope Francis' decision, Gregory was a monk of the Armenian Apostolic Church, which, like other Oriental Orthodox Churches, split off from the rest of Christendom over the Council of Chalcedon in 451 AD. Therefore, Gregory is seen by some as a Monophysite who was in union with neither Catholic nor Eastern Orthodox Christians at the time of his death in 1003.
The Oriental Orthodox churches, among which the Armenian Apostolic Church is numbered, are Miaphysites; however, defenders of the decision have cited historical evidence that Narek Monastery, where Gregory lived and died, was a center of opposition to Monophysitism from inside the Armenian Church[ dubious ]. It is also cited that Gregory of Narek was prior to the move by Pope Francis listed in the Roman Martyrology with a feast day of February 27 and that members of the Armenian Catholic Church have always had a strong devotion to him and his writings.
It was not until 25 January 2021 that the Congregation for Divine Worship and the Discipline of the Sacraments decreed the insertion into the Roman Rite liturgical books of the three Doctors declared by Benedict XVI, along with Gregory of Narek, more recently declared by Pope Francis.
In October 2019, the Polish Catholic Bishops Conference formally petitioned Pope Francis to consider making Pope John Paul II a Doctor of the Church in an official proclamation, in recognition of his contributions to theology, philosophy, and Catholic literature, as well as the formal documents (encyclicals, apostolic letters, bulls, motu proprio documents, homilies, and speeches) that he issued.  The Archbishop of San Salvador, El Salvador has petitioned Pope Francis to name St Oscar Romero, martyred in 1980 while he was archbishop there, who held a doctorate and was a reliably orthodox figure even as he grew to advocate for the plight of his people during the civil war there, as a Doctor of the Church. 
(For earlier authorities on Christian doctrine, see Church Fathers and Ante-Nicene Fathers)* indicates a saint who is also held in high esteem by the Eastern Orthodox Church.
|1.||Gregory the Great*||One of the four Great Latin Fathers||540 (c.)||604||1298||Pope, O.S.B.||Dialogues , Libellus responsionum , Pastoral Care , Moralia in Job|
|2.||Ambrose*||One of the four Great Latin Fathers||340 (c.)||397||1298||Bishop of Milan||Ambrosian hymns, Exameron , De obitu Theodosii|
|3.||Augustine of Hippo*||One of the four Great Latin Fathers; Doctor gratiae|
(Doctor of Grace)
|354||430||1298||Bishop of Hippo (now Annaba)||De doctrina Christiana , Confessions , The City of God , On the Trinity|
|4.||Jerome*||One of the four Great Latin Fathers||347 (c.)||420||1298||Priest, monk||Vulgate, De Viris Illustribus|
|5.||Thomas Aquinas||Doctor angelicus|
|1225||1274||1567||Priest, Theologian, O.P.||Summa Theologiae , Summa contra Gentiles|
|6.||John Chrysostom*||One of the four Great Greek Fathers||347||407||1568||Archbishop of Constantinople||Paschal Homily , Adversus Judaeos|
|7.||Basil the Great*||One of the four Great Greek Fathers||330||379||1568||Bishop of Caesarea||Address to Young Men on Greek Literature , On the Holy Spirit|
|8.||Gregory of Nazianzus*||One of the four Great Greek Fathers||329||389||1568||Archbishop of Constantinople||On God and Christ: The Five Theological Orations and Two Letters to Cledonius|
|9.||Athanasius*||One of the four Great Greek Fathers||298||373||1568||Archbishop of Alexandria||Letters to Serapion|
|1221||1274||1588||Cardinal Bishop of Albano, Theologian, Minister General, O.F.M.||Commentary on the Sentences of Lombard, The Mind's Road to God, Collationes in Hexaemeron|
|11.||Anselm of Canterbury||Doctor magnificus|
|1033 or 1034||1109||1720||Archbishop of Canterbury, O.S.B.||Proslogion , Cur Deus Homo|
|12.||Isidore of Seville*||560||636||1722||Archbishop of Seville||Etymologiae , On the Catholic Faith against the Jews|
|13.||Peter Chrysologus*||406||450||1729||Bishop of Ravenna||Homilies|
|14.||Leo the Great* ||Doctor unitatis Ecclesiae|
(Doctor of the Church's Unity)
|15.||Peter Damian||1007||1072||1828||Cardinal Bishop of Ostia, monk, O.S.B.||De Divina Omnipotentia, Liber Gomorrhianus|
|16.||Bernard of Clairvaux|| Doctor mellifluus |
|1090||1153||1830||Priest, O.Cist.||Sermones super Cantica Canticorum, Apologia ad Guillelmum , Liber ad milites templi de laude novae militiae|
|17.||Hilary of Poitiers*||Doctor divinitatem Christi|
(Doctor of the Divinity of Christ)
|300||367||1851||Bishop of Poitiers||Commentarius in Evangelium Matthaei|
|18.||Alphonsus Liguori||Doctor zelantissimus|
(Most Zealous Doctor)
|1696||1787||1871||Bishop of Sant'Agata de' Goti, C.Ss.R. (Founder)||The Glories of Mary , Moral Theology|
|19.||Francis de Sales||Doctor caritatis|
(Doctor of Charity)
|1567||1622||1877||Bishop of Geneva, C.O.||Introduction to the Devout Life , Letters of Spiritual Direction|
|20.||Cyril of Alexandria*||Doctor Incarnationis|
(Doctor of the Incarnation)
|376||444||1883||Archbishop of Alexandria||Commentaries on the Old Testament, Thesaurus, Discourse Against Arians, Dialogues on the Trinity|
|21.||Cyril of Jerusalem*||315||386||1883||Archbishop of Jerusalem||Catechetical Lectures , Summa doctrinae christianae|
|22.||John Damascene*||676||749||1890||Priest, monk||Fountain of Knowledge, Octoechos|
|23.||Bede the Venerable*||Anglorum doctor|
(Doctor of the English) 
|672||735||1899||Priest, monk, O.S.B.||Ecclesiastical History of the English People , The Reckoning of Time , Liber epigrammatum , Paenitentiale Bedae|
|24.||Ephrem* ||306||373||1920||Deacon||Commentary on the Diatessaron, Prayer of Saint Ephrem, Hymns Against Heresies|
|25.||Peter Canisius||1521||1597||1925||Priest, S.J.||A Summary of Christian Teachings|
|26.||John of the Cross||Doctor mysticus|
|1542||1591||1926||Priest, mystic, O.C.D. (Reformer)||Spiritual Canticle , Dark Night of the Soul , Ascent of Mount Carmel|
|27.||Robert Bellarmine||1542||1621||1931||Archbishop of Capua, Cardinal, Theologian, S.J.||Disputationes de Controversiis|
|28.||Albertus Magnus ||Doctor universalis|
|1193||1280||1931||Bishop of Regensburg, Theologian, O.P.||On Cleaving to God, On Fate|
|29.||Anthony of Padua||Doctor evangelicus|
|1195||1231||1946||Priest, O.F.M.||Sermons for Feast Days|
|30.||Lawrence of Brindisi||Doctor apostolicus|
|1559||1619||1959||Priest, Diplomat, O.F.M. Cap.||Mariale|
|31.||Teresa of Ávila ||Doctor orationis|
(Doctor of Prayer)
|1515||1582||1970||Mystic, O.C.D. (Reformer)||La Vida de la Santa Madre Teresa de Jesús, The Way of Perfection, The Interior Castle|
|32.||Catherine of Siena||1347||1380||1970||Mystic, O.P. (Third Order Dominican)||The Dialogue of Divine Providence|
|33.||Thérèse of Lisieux||Doctor Fiduciae|
(Doctor of Confidence)
|1873||1897||1997||O.C.D. (Nun)||The Story of a Soul|
|34.||John of Ávila||1500||1569||2012||Priest, Mystic||Audi, filia; Spiritual Letters|
|35.||Hildegard of Bingen||1098||1179||2012||Visionary, theologian, polymath, composer, abbess O.S.B., physician, philosopher||Scivias, Liber Vitae Meritorum, Liber Divinorum Operum, Ordo Virtutum,|
|36.||Gregory of Narek ||951||1003||2015||Monk, poet, mystical philosopher, theologian||Book of Lamentations|
|37.||Irenaeus of Lyon* ||Doctor unitatis|
(Doctor of Unity) 
|130||202||2022||Bishop, theologian, Martyr||Proof of the Apostolic Preaching, Against Heresies|
In addition, parts of the Catholic Church have recognised other individuals with this title. In Spain, Fulgentius of Cartagena,  Ildephonsus of Toledo  and Leander of Seville have been recognized with this title.  [ self-published source? ] In 2007 Pope Benedict XVI, in his encyclical Spe Salvi , called Maximus the Confessor "the great Greek Doctor of the Church",  though the Congregation for the Causes of Saints considers this declaration an informal one. 
Though not named Doctors of the Church or even canonized, many of the more celebrated doctors of theology and law of the Middle Ages were given an epithet which expressed the nature of their expertise. Among these are Bl. John Duns Scotus, Doctor subtilis (Subtle Doctor); Bl. Ramon Llull, Doctor illuminatus (Illuminated Doctor); Bl. John of Ruysbroeck, Doctor divinus ecstaticus (Ecstatic Doctor); Alexander of Hales, Doctor irrefragabilis (Unanswerable Doctor); Roger Bacon, "Doctor Mirabilis" (Wondrous Doctor); Gregory of Rimini, Doctor authenticus (Authentic Doctor); Jean Gerson, Doctor christianissimus (Most Christian Doctor); Nicholas of Cusa, Doctor christianus (Christian Doctor); and the priest and professor Francisco Suárez, Doctor eximius (Exceptional Doctor). In this same line are the Latin epithets assigned to various Doctors of the Church from the Middle Ages onwards, some displaying more enthusiasm than clarity.[ citation needed ]
The Syro-Malabar Catholic Church recognises Ambrose, Jerome, Gregory, Augustine, Athanasius, Basil, Gregory of Nazianzus and John Chrysostom, as well as Ephrem the Syrian, Isaac the Elder, Pope Leo I, John of Damascus, Cyril of Alexandria, Cyril of Jerusalem, Epiphanius of Salamis and Gregory of Nyssa.   
The Chaldean Catholic Church honours as doctor Polycarp, Eustathius of Antioch, Meletius, Alexander of Jerusalem, Athanasius, Basil, Cyril of Alexandria, Gregory Nazianzus, Gregory of Nyssa, John Chrysostom, Fravitta of Constantinople, Ephrem the Syrian, Jacob of Nisibis, Jacob of Serugh, Isaac of Armenia, Isaac of Nineveh, and Maruthas of Martyropolis.    
The Eastern Orthodox Church honors many of the pre-schism saints as well, but the term "Doctor of the Church" is not applied in the same way. One consistent use of the category is the trio of Basil the Great, Gregory of Nazianzus and John Chrysostom, recognized as universal teachers and known as the Three Holy Hierarchs.  The church also recognizes three saints with the title Theologos (Theologian): John the Evangelist, Gregory of Nazianzus and Symeon the New Theologian. 
Russian Orthodox Church commemorates on 19 July feast of Three Holy Russian Hierarchs: Demetrius of Rostov, Mitrophan of Voronezh and Tikhon of Zadonsk. 
The Armenian Apostolic Church recognizes the Twelve Holy Teachers ( Vardapets ) of the Church
They also recognize their own saints Mesrob, Yeghishe, Movses Khorenatsi, David the Invincible, Gregory of Narek,  Nerses III the Builder, and Nerses of Lambron as "Doctors of the Armenian Church" or the "Armenian Doctors."  
The Assyrian Church of the East recognizes Yeghishe, Diodorus of Tarsus, Theodore of Mopsuestia, and Nestorius as Doctors of the Church. 
The churches of the Anglican Communion tend not to use the term "Doctor of the Church" in their calendars of saints, preferring expressions such as Teacher of the Faith. Those thus recognized include figures from before and after the Reformation, most of whom are chosen among those already recognized as in the Catholic Church and Eastern Orthodox Church. Those designated as Teachers of the Faith in the Church of England's calendar of saints are as follows:
Since all of the above appear in the calendar at the level of Lesser Festival or Commemoration, their celebration is optional. Similarly, because "In the Calendar of the Saints, diocesan and other local provision may be made to supplement the national Calendar",  those Doctors of the Church recognized by the Catholic Church may also be celebrated in the Church of England.
The Lutheran calendar of saints does not use the term "Doctor of the Church." The calendar of the Lutheran Church–Missouri Synod refers to Martin Luther by the title of "Doctor" in recognition of his academic degree, Doctor of Theology from the University of Wittenberg in 1512.
Gregory of Nazianzus, also known as Gregory the Theologian or Gregory Nazianzen, was a 4th-century Archbishop of Constantinople and theologian. He is widely considered the most accomplished rhetorical stylist of the patristic age. As a classically trained orator and philosopher, he infused Hellenism into the early church, establishing the paradigm of Byzantine theologians and church officials.
Basil of Caesarea, also called Saint Basil the Great, was a bishop of Caesarea Mazaca in Cappadocia, Asia Minor. He was an influential theologian who supported the Nicene Creed and opposed the heresies of the early Christian church, fighting against both Arianism and the followers of Apollinaris of Laodicea. His ability to balance his theological convictions with his political connections made Basil a powerful advocate for the Nicene position.
Divine Liturgy or Holy Liturgy is the Eucharistic service of the Byzantine Rite, a liturgical rite developed from the Antiochene Rite of Christian liturgy which is that of the Ecumenical Patriarchate of Constantinople. As such, it is used in the Eastern Orthodox, the Greek Catholic Churches, and the Ukrainian Lutheran Church. Although the same term is sometimes applied in English to the Eucharistic service of Armenian Christians, both of the Armenian Apostolic Church and of the Armenian Catholic Church, they use in their own language a term meaning "holy offering" or "holy sacrifice". Other churches also treat "Divine Liturgy" simply as one of many names that can be used, but it is not their normal term.
The Cappadocian Fathers, also traditionally known as the Three Cappadocians, are Basil the Great (330–379), who was bishop of Caesarea; Basil's younger brother Gregory of Nyssa, who was bishop of Nyssa; and a close friend, Gregory of Nazianzus (329–389), who became Patriarch of Constantinople. The Cappadocia region, in modern-day Turkey, was an early site of Christian activity, with several missions by Paul in this region.
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.
Grigor Narekatsi was an Armenian mystical and lyrical poet, monk, and theologian. He is venerated as a saint in the Armenian Apostolic and Catholic Churches and was declared a Doctor of the Church by Pope Francis in 2015.
The Litany of the Saints is a formal prayer of the Roman Catholic Church as well as the Old Catholic Church, Anglo-Catholic communities, and Western Rite Orthodox communities. It is a prayer to the Triune God, which also includes invocations for the intercession of the Blessed Virgin Mary, the Angels and all the martyrs and saints upon whom Christianity was founded, and those recognised as saints through the subsequent history of the church. Following the invocation of the saints, the Litany concludes with a series of supplications to God to hear the prayers of the worshippers. It is most prominently sung during the Easter Vigil, All Saints' Day, and in the liturgy for conferring Holy Orders, the Consecration of a Virgin and reception of the perpetual vows of a religious or a diocesane hermit.
The history of the Catholic Church is integral to the history of Christianity as a whole. It is also, according to church historian, Mark A. Noll, the "world's oldest continuously functioning international institution." This article covers a period of just under two thousand years.
Alphabetical list of Eastern Christianity-related articles on English Wikipedia
The General Roman Calendar is the liturgical calendar that indicates the dates of celebrations of saints and mysteries of the Lord in the Roman Rite of the Catholic Church, wherever this liturgical rite is in use. These celebrations are a fixed annual date, or occur on a particular day of the week. Examples are the Feast of the Baptism of the Lord in January and the Feast of Christ the King in November.
In the Calendar of the Scottish Episcopal Church, each holy and saint's day listed has been assigned a number which indicates its category. It is intended that feasts in categories 1 - 4 should be kept by the whole church. Days in categories 5 and 6 may be kept according to diocesan or local discretion. Commemorations not included in this Calendar may be observed with the approval of the bishop.
This is a calendar of saints list for the Armenian Apostolic Church.
The Three Hierarchs of Eastern Christianity refers to Basil the Great, Gregory the Theologian and John Chrysostom. They were highly influential bishops of the early church who played pivotal roles in shaping Christian theology. In Eastern Christianity they are also known as the Three Great Hierarchs and Ecumenical Teachers, while in Roman Catholicism the three are honored as Doctors of the Church. The three are venerated as saints in Eastern Orthodoxy, Catholicism, Anglicanism, and other Christian churches.
A vardapet is a title given to highly educated hieromonks in the Armenian Apostolic Church. It has been variously translated as 'doctor', 'doctor-monk', 'archimandrite', or 'doctor of theology'.
Only-Begotten Son, sometimes called "Justinian's Hymn", the "Anthem of Orthodoxy" and/or the "Hymn of the Incarnation", is an ancient Christian hymn that was composed prior to the middle of the 6th century. It is chanted at the end of the Second Antiphon during the Divine Liturgies of St John Chrysostom, St Basil the Great and of St Gregory the Illuminator, and at the Little Entrance during the Liturgy of Saint James.
In the 5th century in Christianity, there were many developments which led to further fracturing of the State church of the Roman Empire. Emperor Theodosius II called two synods in Ephesus, one in 431 and one in 449, that addressed the teachings of Patriarch of Constantinople Nestorius and similar teachings. Nestorius had taught that Christ's divine and human nature were distinct persons, and hence Mary was the mother of Christ but not the mother of God. The Council rejected Nestorius' view causing many churches, centered on the School of Edessa, to a Nestorian break with the imperial church. Persecuted within the Roman Empire, many Nestorians fled to Persia and joined the Sassanid Church thereby making it a center of Nestorianism. By the end of the 5th century, the global Christian population was estimated at 10-11 million. In 451 the Council of Chalcedon was held to clarify the issue further. The council ultimately stated that Christ's divine and human nature were separate but both part of a single entity, a viewpoint rejected by many churches who called themselves miaphysites. The resulting schism created a communion of churches, including the Armenian, Syrian, and Egyptian churches, that is today known as Oriental Orthodoxy. In spite of these schisms, however, the imperial church still came to represent the majority of Christians within the Roman Empire.
The Church Fathers, Early Church Fathers, Christian Fathers, or Fathers of the Church were ancient and influential Christian theologians and writers who established the intellectual and doctrinal foundations of Christianity. The historical period in which they worked became known as the Patristic Era and spans approximately from the late 1st to mid-8th centuries, flourishing in particular during the 4th and 5th centuries, when Christianity was in the process of establishing itself as the state church of the Roman Empire.
Articles related to Christianity include:
The following outline is provided as an overview of and topical guide to the Catholic Church:
The Popular Patristics Series is a series of volumes of original English translations of mainly first millennium Christian texts published by St. Vladimir's Seminary Press. The aim of the series is "to provide readable and accurate translations of a broad range of early Christian literature to a wide audience—from students of Christian history and theology to lay Christians reading for spiritual benefit." It currently comprises 61 volumes. The texts are principally translated from Greek, but some Latin, Syriac and Coptic writers are included. Each volume is translated by a recognized patristic scholar and also contains a concise but comprehensive introduction to the patristic author and their works. John Behr was the longtime series editor until 2020, when he handed off the role to Bogdan Bucur and assistant editor Ignatius Green.