History of Christianity

==Early Middle Ages (600–1100)==
{{Main|Christianity in the Middle Ages}}
{{See also|Christianization of Europe|Christianity in the 7th century|Christianity in the 8th century}}{{Further|Syriac Christianity|Church of the East|Carolingian Renaissance|Carolingian church|Donation of Pepin|Frankish Papacy|Celtic Christianity|Germanic Christianity}}
In the early part of this period Christianity's “nerve centers” remained urban bishoprics. Frankish Gaul had 116 bishops. Visigothic Spain had 66, Italy had 237, and North Africa had 242. The Sassanian Empire supported over 50 bishops. The church of Armenia had 20. With over 680 bishops, Byzantium was the center of the Christian world.{{sfn|Brown|2008|pp=7, 13}}

In the 600s, Byzantium faced invasion by the [[Persian Empire]], which took land, and the rise of Islam and the establishment of an Arab Empire to Byzantium's east, which also took land.{{sfn|Louth|2008|p=47}}{{refn|group=note| The Sassanid Persian Empire was destroyed by the Muslims in 637.{{sfn|Louth|2008|p=46}} By 635, upper-class Christian refugees had already moved [[Church of the East in China|further east to China]] at [[Chang'an|Hsian-fu]].{{sfn|Brown|2008|pp=3, 5–6}}}} In the 720s, the Byzantine Emperor [[Leo III the Isaurian]] banned the pictorial representation of Christ, saints, and biblical scenes, destroying much early art history. The West condemned Leo's [[iconoclasm]].{{sfn|Halsall|2021}} By the nine hundreds, Byzantine culture began to recover.{{sfn|Louth|2008|p=46}}{{sfn|Shepard|2006|p=3}}{{sfn|Matthews|Platt|1992|p=182}} By the tenth and early eleventh centuries, Orthodoxy was again manifested in the realms of art, scholarship, monastic revival and missionary expansion.{{sfn|Louth|2008|p=46}} 

Christianity in the 600s saw itself as established, but religion in the Middle Ages was not unified and piously Christian.{{sfn|Van Engen|1986|pp=519, 552}}{{sfn|Brown|2008|p=6}} Christianity and many of the old beliefs existed side-by-side in the emerging Western European world.{{sfn|Van Engen|1986|pp=519, 521, 526}}{{sfn|Brown|2008|pp=7–8}} 

The church of this period allowed "simple folk" who held an "implicit faith" without complete doctrinal understanding.{{sfn|Van Engen|1986|pp=545, 551}}{{sfn|Swanson|2021|p=7}} These centuries stand alone as a period without major controversy over orthodoxy.{{sfn|Matter|2008|pp=510, 516, 518}} 

Throughout this period, the western church functioned like an early version of a welfare state sponsoring public hospitals, orphanages, hospices, and hostels (inns).{{sfn|Blainey|2011|pp=214–215}}{{sfn|Butler|1919|loc=intro.}} The steadily increasing number of monasteries and convents supplied food during famine and distributed food to the poor.{{sfn|Matthews|Platt|1992|p=198}} Monasteries actively preserved ancient texts, classical craft and artistic skills, while maintaining an intellectual and spiritual culture. They supported [[literacy]] within their schools, [[Scriptorium|scriptoria]] and libraries.{{sfn|Woods|Canizares|2012|p=5}}{{sfn|LeGoff|2000|p=120}} They were models of productivity and economic resourcefulness, teaching their local communities animal husbandry, cheese making, wine making, and various other skills.{{sfn|Dunn|2016|p=60}} 

Medical practice was highly important and medieval monasteries are best known for their contributions to medical tradition. They also made advances in sciences such as astronomy, and St. Benedict's Rule (480–543) impacted politics and law.{{sfn|Butler|1919|loc=intro.}}{{sfn|Koenig|King|Carson|2012|pp=22–24}} The formation of these organized bodies of believers gradually carved out a series of social spaces with some amount of independence, distinct from political and familial authority, thereby revolutionizing social history.{{sfn|Haight|2004|p=273}}

The Middle Ages were complex, with diverse elements, but the concept of [[Christendom|''Christendom'']] was pervasive and unifying.{{sfn|Van Engen|1986|p=532}} Medieval writers and ordinary folk used the term to identify themselves, their religious culture, and even their civilization.{{sfn|Van Engen|1986|pp=526, 539-541}}{{sfn|Whalen|2015|p=5}}{{refn|group=note| Membership in Christendom began with baptism at birth. Participation included rudimentary knowledge of the [[Apostles' Creed]] and the [[Lord's Prayer]]. From peasant to pope, all were required to rest on Sunday and feast days, attend mass, fast at specified times, confess once a year (after 1215), take communion at Easter, pay various fees, tithes and alms for the needy, and receive last rites at death. These were overseen and enforced by the king and his lords and bishops.{{sfn|Van Engen|1986|p=540}}}} From the ninth to the eleventh century, Christendom encompassed a loose federation of churches across the European continent under the spiritual headship of the Pope.{{sfn|Thompson|2016|p=176}} However, the Pope had no clearly established authority over those churches. He gave little general direction, and the few councils that occur in this period were called by kings not popes.{{sfn|Thompson|2016|p=176}}

A symbiotic relationship existed between ecclesiastical institutions and civil governments between the sixth and the mid-eighth centuries with churches dependent upon lay rulers; ruling kings, dukes and counts made all appointments to ecclesiastical offices on their land.{{sfn|Thompson|2016|pp=176–177}}{{sfn|Althoff|2019b|pp=173, 175}}{{sfn|Eichbauer|2022|p=3}}

===Church and society===
{{See also|History of European universities}}
[[File:Mapa cister.svg|thumb|The spread of [[Cistercians]] from their original sites in [[Western Europe|Western]]-[[Central Europe]] during the Middle Ages|alt=this is an image of a map showing the original sites of the Cistercians in Central Europe]]
There was substantial growth in heretical movements over the five or six decades at the end of the tenth and beginning of the eleventh centuries. Nobles were overstepping in church affairs, many clergy were untrained, church posts were being bought and sold (simony), and there was a general sexual laxity.{{sfn|Dowley|2018|p=157}}{{sfn|Matter|2008|pp=529-530}} Religious leaders spoke out against the moral abuses of other ecclesiastical leaders.{{sfn|Matter|2008|p=529}} The eleventh century became an age of religious reform and renewal.{{sfn|Dowley|2018|p=157}}{{sfn|Matter|2008|pp=529-530}}

Owing to its stricter adherence to the reformed [[Rule of St Benedict|Benedictine rule]], the [[Cluny Abbey|Abbey of Cluny]], first established in 910, became the leading center of Western monasticism into the early twelfth century.{{sfn|Matthews|Platt|1992|p=216, 218}}{{sfn|Constable|1998|pp=4–5}} The [[Cistercians|Cistercian movement]] was a second wave of reform. After 1098, they became a primary force of [[Medieval technology|technological advancement and diffusion in medieval Europe]].{{sfn|Matthews|Platt|1992|p=218}}
[[File:ChesterMysteryPlay 300dpi.jpg|thumb|Copper engraving by David Gee (1793-1872) that recreates a 15th-century Passion play. Details are based on written accounts, including pageant wagon design and the people in the street.|alt=re-creation of a fifteenth century mystery play ]]
Beginning in the twelfth century, the pastoral [[Franciscans|Franciscan Order]] was instituted by the followers of [[Francis of Assisi]]; later, the [[Dominican Order]] was begun by [[Saint Dominic|St. Dominic]]. Called [[Mendicant orders]], they represented a change in understanding a monk's calling as contemplative, instead seeing it as a call to actively reform the world through preaching, missionary activity, and education.{{sfn|Fox|1987|p=298}}{{sfn|Jestice|1997|p=1, 5–6}} 

The means and methods of teaching an illiterate populace included mystery plays (which had developed out of the mass), wall paintings, vernacular sermons and treatises, and saints' lives in epic form.{{sfn|Van Engen|1986|p=552}} Rituals, art, literature, and cosmology were shaped by Christian norms but also contained some pre-Christian elements.{{sfn|Van Engen|1986|p=549}} Christian motifs could function in non-Christian ways, while practices of non-Christian origin became endowed with Christian meaning.{{sfn|Van Engen|1986|p=550}} In the synthesis of old and new, influence cut both ways, but the cultural dynamic lay with Christianization.{{sfn|Van Engen|1986|pp=550–552}}

As literacy spread, [[Medieval university|western universities]], the first institutions of higher education since the sixth century, began as [[cathedral school]]s, or were directly formed into self-governing corporations chartered by popes and kings.{{sfn|Verger|1995|p=257}}{{sfn|Rüegg|1992|pp=xix–xx}}{{sfn|Den Heijer|2011|p=65|ps=: "Many of the medieval universities in Western Europe were born under the aegis of the Catholic Church, usually as cathedral schools or by papal bull as Studia Generali"}} Divided into faculties which specialized in [[law]], [[medicine]], [[theology]] or [[liberal arts]], each held ''[[quodlibeta]]'' (free-for-all) theological debates amongst faculty and students and awarded degrees.{{sfn|Matthews|Platt|1992|p=221}}{{sfn|Piron|2006|pp=404–406}} The earliest were the [[University of Bologna]] (1088), the [[University of Oxford]] (1096), and the [[University of Paris]] where the faculty was of international renown ({{circa|1150}}).

=== Regional developments (600–1100) ===
{{See also|Christianity in the Middle Ages|Christianization of Serbs|Christianization of Bohemia|Christianization of Moravia|Crusades|Northern Crusades}}
{{Further|Eastern Orthodox opposition to papal supremacy|History of the Eastern Orthodox Church|History of Oriental Orthodoxy|East–West Schism|Degrees of Eastern Orthodox monasticism}}
[[File:Rome, S. Maria del Rosario; Madonna of San Sisto (after restoration).png|thumb|upright=.8|The Madonna of San Sisto (after restoration) dating from the 6th century is perhaps the oldest existing image of Mary|alt=restored painting from the 6th century of Mary mother of Jesus]]
In the West, [[Charlemagne]] began the [[Carolingian Renaissance]] in the 800s. Sometimes called a Christian renaissance, it was a period of intellectual and cultural revival of literature, arts, and scriptural studies, a renovation of law and the courts, and the promotion of literacy.{{sfn|Collins|1998|p=1}}

[[Gregorian Reform]] (1050–1080) established new canon law. That included laws requiring the consent of both parties for marriage, a minimum age for marriage, and laws making it a sacrament.{{sfn|Shahar|2003|p=33}}{{sfn|Witte|1997|pp=20–23}} This made the union a binding contract, which meant abandonment was prosecutable with dissolution of marriage overseen by Church authorities.{{sfn|Witte|1997|pp=29–30}} Although the Church abandoned tradition to allow women the same rights as men to dissolve a marriage, in practice men were granted dissolutions more frequently than women.{{sfn|Witte|1997|pp=20, 25}}{{sfn|Shahar|2003|p=18}}

The veneration of the [[Virgin Mary]] grew dramatically in the Middle Ages within the monasteries in western medieval Europe. It spread through society and flourished in the late eleventh and twelfth centuries with the emergence of [[affective piety]], which grew from empathy with the human Christ and his suffering, and exhibited itself in compassion toward the suffering of others. People of the time praised Mary for making God tangible.{{sfn|Shoemaker|2016|p=21}}{{sfn|Fulton|2009|pp= 284–285, 294}} 

Throughout the Middle Ages, abbesses and female superiors of monastic houses were powerful figures whose influence could rival that of male bishops and abbots.{{sfn|Oestereich|1907}}{{sfn|Hunt|2020}} 

Having begun in Christianity's first 500 years, [[Christian mysticism]] came to its full flowering in the Middle Ages.{{sfn|King|2001|pp=4, 22}}{{sfn|Hollywood|2009|pp=298–299}} This period included a longing for the genuine "apostolic life" with particular sensitivity to the practice of voluntary holy poverty.{{sfn|Van Engen|1986|p=523}}

====Near East, Byzantium and schism====
[[File:Church of the East in the Middle Ages.svg|thumb|The [[Church of the East]] during the Middle Ages|alt=map showing Church of the East in the Middle Ages]]
[[File:Hagia Sophia in Istanbul (focused on the original Roman building).jpg|thumb|[[Hagia Sophia]] was the religious and spiritual centre of the [[Eastern Orthodox Church]] for nearly one thousand years. The [[Hagia Sophia]] and the [[Parthenon]] were converted into mosques. Violent persecutions of Christians were common and reached their climax in the [[Armenian genocide|Armenian]], [[Assyrian genocide|Assyrian]], and [[Greek genocide|Greek]] genocides.{{sfn|Barton|1998b|p=vii}}{{sfn|Morris|Ze'evi|2019|pp=3–5}}|alt=image of Hagia Sophia]]
Towards the end of the sixth century, two main kinds of Christian communities had formed in [[Syria]], [[Egypt]], [[Persia]], and [[Armenia]]: urban churches which upheld the [[Council of Chalcedon]] (451 CE) saying Christ had one human/divine nature, and Nestorian churches which came from the desert monasteries asserting Christ had two separate natures.{{sfn|Dorfmann-Lazarev|2008|pp=65-66}} The distinctive doctrinal and cultural identities of these churches played a decisive role in their history after the Arab conquest.{{sfn|Dorfmann-Lazarev|2008|pp=66-67}}

Intense missionary activity between the fifth and eighth centuries led to eastern [[Iran]], [[Arabia]], central [[Asia]], China, and the coasts of [[India]] and Indonesia adopting [[Nestorian Christianity]]. Syrian Nestorians had settled in the [[Persian Empire]] which spread over modern [[Iraq]], [[Iran]], and parts of Central Asia.{{sfn|Brown|2008|p=5}}{{sfn|Micheau|2006|p=378}} The rural areas of Upper Egypt were all Nestorian. [[Copts|Coptic]] missionaries spread the faith up the Nile to [[Nubia]], [[Eritrea]], and [[Ethiopia]].{{sfn|Dorfmann-Lazarev|2008|pp=66-67}}

From the early 600s, a series of Arab military campaigns conquered Syria, Mesopotamia, Egypt and Persia.{{sfn|Matthews|Platt|1992|pp=192, 199}}{{sfn|Barton|2009|p=xvii}} Conquest, conflict, and persecution exercised a lasting influence on the churches in these regions.{{sfn|Dorfmann-Lazarev|2008|p=85}} Under Islamic rule, persecution of non-Muslims was particularly devastating in cities where Chalcedonian churches were located. The monastic background of the Nestorians made their churches more remote, so they often escaped direct attention. In the following centuries, it was the Nestorian churches who were best able to survive and cultivate new traditions.{{sfn|Dorfmann-Lazarev|2008|p=66}}

[[Mozarabs|''Andalusi Christians'']],{{sfn|Bennison|2016|p=166}} from the [[Iberian Peninsula]] lived under [[Muslims|Muslim]] rule from [[Muslim conquest of Spain|711]] to [[Granada War|1492]].{{sfn|Fierro|2008|pp=137–164}} The martyrdoms of forty-eight Christians for defending their Christian faith took place in [[Emirate of Córdoba|Córdoba]] between 850 and 859.{{sfn|Graves|1964|p=644}}{{sfn|Sahner|2020|pp=1–28}}{{sfn|Fierro|2008|pp=137–164}}{{sfn|Trombley|1996|pp=581–582}} Executed under [[Abd al-Rahman II]] and [[Muhammad I of Córdoba|Muhammad I]], the record shows the executions were for capital violations of Islamic law, including [[Apostasy in Islam|apostasy]] and [[Islam and blasphemy|blasphemy]].{{sfn|Sahner|2020|pp=1–28}}{{sfn|Fierro|2008|pp=137–164}}{{sfn|Trombley|1996|pp=581–582}}

Many cultural, geographical, geopolitical, and linguistic differences between East and West existed. There were disagreements over whether Pope or Patriarch should lead the Church, whether mass should be conducted in Latin or Greek, whether priests must remain celibate, and other points of doctrine such as the ''[[Filioque|Filioque Clause]]'' and Nestorianism.{{sfn|Matthews|Platt|1992|p=185}}{{sfn|Meyendorff|1979|p=intro.}}{{sfn|Lorenzetti|2023}} Eventually, this produced the [[East–West Schism]], also known as the "Great Schism" of 1054, which separated the Church into Western Catholicism and Eastern Orthodoxy.{{sfn|Meyendorff|1979|p=intro.}}

====Crusade====
[[File:Map Crusader states 1135-en.svg|thumb|The [[Kingdom of Jerusalem]] and the [[Crusader states]] with their strongholds in the [[Holy Land]] at their height, between the [[First Crusade|First]] and the [[Second Crusade|Second]] Crusade (1135)|alt=image of Map Crusader states 1135]] 
After 1071, when the [[Seljuk Turks]] closed access for Christian pilgrimages and defeated the Byzantines at [[Battle of Manzikert|Manzikert]], the Emperor [[Alexius I]] asked for aid from [[Pope Urban II]]. Historian [[Jaroslav Folda]] writes that Urban II responded by calling upon the knights of Christendom at the [[Council of Clermont]] on 27 November 1095, to "go to the aid of their brethren in the Holy Land", an appeal aimed largely at those with sufficient wealth and position to subsidize their own journey.{{sfn|Folda|1995|p=141}}{{sfn|Tyerman|1992|pp=15–16}} The [[First Crusade]] captured Antioch in 1099, then Jerusalem, establishing the [[Kingdom of Jerusalem]].{{sfn|Folda|1995|p=36}}

The [[Second Crusade]] began after [[County of Edessa|Edessa]] was taken by Islamic forces in 1144.{{sfn|Fonnesberg-Schmidt|2007|p=65}} Christians lost Jerusalem in 1187 through the catastrophic defeat of the Franks at the [[Battle of Hattin|Horns of Hattin]].{{sfn|Folda|1995|p=150}} The [[Third Crusade]] did not regain the major Holy sites.{{sfn|Folda|1995|p=150}}

The [[Fourth Crusade]], begun by [[Pope Innocent III|Innocent III]] in 1202 was subverted by the Venetians. They funded it, then ran out of money and instructed the crusaders to go to Constantinople and get money there. Crusaders sacked the city and other parts of Asia Minor, established the [[Latin Empire]] of Constantinople in Greece and Asia Minor, and contributed to the downfall of the Byzantine Empire. Five numbered crusades to the Holy Land culminated in the [[Siege of Acre (1291)|siege of Acre]] in 1291, essentially ending Western presence in the Holy Land.{{sfn|Marshall|1994|p=1}} Crusades led to the development of national identities in European nations, increased division with the East, and produced cultural change for all involved.{{sfn|Kostick|2010|pp=2–6}}{{sfn|Matthews|Platt|1992|pp=192–195}}

====Investiture and papal primacy====
[[File:Canossa-gate.jpg|thumb|[[Henry IV, Holy Roman Emperor|Henry IV]], the [[Holy Roman Emperor]] at the gate of [[Canossa Castle]] in 1077, during the [[Investiture controversy]].|alt=image of painting of Henry IV, Holy Roman Emperor, at the gate of Canossa Castle in 1077]]
The [[Investiture controversy]] began in the [[Holy Roman Empire]] in 1078. Specifically a dispute between the Holy Roman Emperor [[Henry IV, Holy Roman Emperor|Henry IV]] and [[Pope Gregory VII]] (1073-1085) concerning who would appoint, [[investiture|''invest'']], bishops, it was more generally, a conflict between king and pope over control of the church.{{sfn|Garrett|1987|pp=5–7}}{{sfn|Grzymała-Busse|2023|p=51}}{{sfn|Thompson|2016|pp=176–182}}{{sfn|Dowley|2018|p=159}} The Church had become committed to the doctrine of papal supremacy by the end of the ninth century, but it wasn't until the eleventh century that Gregory recorded a series of formal statements strongly asserting papal supremacy saying the church could no longer be treated as servant to the state. {{sfn|Thompson|2016|pp=177-178}}{{sfn|MacCulloch|2009|pp=324, 374}}{{sfn|Althoff|2019a|p=199}} 

Ending lay investiture would undercut the power of the Holy Roman Emperor and the ambitions of the [[European nobility]], but allowing lay investiture to continue meant the Pope's authority over his own people was almost non-existent.{{sfn|Grzymała-Busse|2023|pp=51–52}}{{refn|group=note|Bishoprics being merely lifetime appointments, a king could better control their powers and revenues than those of hereditary noblemen. Even better, he could leave the post vacant and collect the revenues, theoretically in trust for the new bishop, or give a bishopric to pay a helpful noble.{{sfn|Grzymała-Busse|2023|pp=51–52}} The Roman Catholic Church wanted to end lay investiture to end this and other abuses, to reform the episcopate and provide better [[pastoral care]] and separation of church and state.{{sfn|Grzymała-Busse|2023|p=25}} Pope Gregory VII issued the ''[[Dictatus Papae]]'', which declared that the pope alone could appoint bishops.{{sfn|Grzymała-Busse|2023|p=25}} Henry IV's rejection of the decree led to his [[Excommunication (Catholic Church)|excommunication]] and a ducal revolt. Eventually, Henry IV received absolution after a [[Road to Canossa|dramatic public penance]], though the [[Saxon revolt of 1077–1088|Great Saxon Revolt]] and conflict of investiture continued.{{sfn|Garrett|1987|p=8}}}} Disobedience to the Pope became equated with heresy.{{sfn|Althoff|2019b|p=175}} Before this, kings had been largely exempt from the requirement of obedience to the Pope because they occupied a special position of their own based on [[Divine right of kings|divine right]].{{sfn|Althoff|2019a|p=191}}  

It took "five decades of excommunications, denunciations and mutual depositions...spanning the reign of two emperors and six popes" only to end inconclusively in 1122.{{sfn|Grzymała-Busse|2023|p=52}}{{sfn|MacCulloch|2009|p=375}} A similar controversy occurred in England.{{sfn|Vaughn|1980|pp=61–86}}