Part ofa series on
Christianity
Jesus Christ Nativity Baptism Ministry Crucifixion Resurrection Ascension
Bible Foundations Old Testament New Testament Gospel Canon Church Creed New Covenant
Theology God Trinity Father Son Holy Spirit Apologetics Baptism Christology History of theology Mission Salvation Universalism
History Tradition Apostles Peter Paul Mary Early Christianity Church Fathers Constantine Councils Augustine Ignatius East–West Schism Crusades Aquinas Reformation Luther
Denominations (full list) Nicene Catholic Latin Eastern Old Catholic Independent Catholic Sedevacantism Eastern Orthodox Oriental Orthodox Church of the East Protestant Adventist Anabaptist Anglican Baptist Free Evangelical Lutheran Methodist Moravian [Hussite] Pentecostal Plymouth Brethren Quaker Reformed United Protestant Waldensian Non-denominational Christianity Restorationist Christadelphians Iglesia ni Cristo Irvingians Jehovah's Witnesses Latter Day Saints The Church of Jesus Christ of Latter-day Saints Members Church of God International The New Church (Swedenborgian) Unitarians and Universalists
Related topics Civilization Criticism Culture Ecumenism Glossary Index Liturgy Other religions Prayer Sermon Symbolism Worship
Glossary Index Outline  Christianity portal
v t e

In the year before theFirst Council of Constantinople in 381,Nicene Christianity became the official religion of theRoman Empire whenTheodosius I, emperor of the East,Gratian, emperor of the West, and Gratian's junior co-rulerValentinian II issued theEdict of Thessalonica in 380,^[1] which recognized thecatholicorthodoxy,^[a] as defined by theCouncil of Nicea, as the Roman Empire'sstate religion.^[3][4][5][6] Historians refer to the imperial church in a variety of ways: as thecatholic church, theorthodox church, theimperial church, theRoman church, or theByzantine church, although some of those terms are also used for wider communions extending outside the Roman Empire.^[7] TheEastern Orthodox Church,Oriental Orthodoxy, and theCatholic Church all claim to stand in continuity from the Nicene church to which Theodosius granted recognition. Political differences between the Eastern Roman Empire and the PersianSassanid Empire led to the separation of theChurch of the East in 424. Doctrinal split within the Roman imperial church led to the independence of the early Oriental Orthodoxy. The fall of the Western Roman Empire initiated the gradual separation betweenEastern andWestern Christianity, which culminated in theEast-West schism of 1054. The Western church evolved into theLatin Catholic Church while the Eastern church body that remained under the patronage of the Eastern empire evolved into theGreek Orthodox Church.

Earlier in the 4th century, following theDiocletianic Persecution of 303–313 and theDonatist controversy that arose in consequence,Constantine the Great had convened councils of bishops to define theorthodoxy of the Christian faith and to expand on earlier Christian councils. A series ofecumenical councils convened by successive Roman emperors met during the 4th and the 5th centuries, but Christianity continued to suffer rifts and schisms surrounding thetheological andchristological doctrines ofArianism,Nestorianism,Miaphysitism, andDyophysitism. In the 5th century, theWestern Roman Empire decayed as apolity; invaders sackedRome in410 and in455, andOdoacer, an Arian barbarian warlord, forcedRomulus Augustus, the last nominal Western Emperor,to abdicate in 476. However, apart from the aforementioned schisms, the church as an institution persisted incommunion, if not without tension, between theEast andWest. In the 6th century, theByzantine armies of theByzantine EmperorJustinian I recovered Italy and other regions of the Western Mediterranean shore. TheByzantine Empire soon lost most of these gains, but it held Rome, as part of theExarchate of Ravenna, until 751, a period known inchurch history as theByzantine Papacy. Theearly Muslim conquests of the 7th–9th centuries would begina process of converting most of thethen-Christian world inthe Levant,Middle East,North Africa, regions ofSouthern Italy and theIberian Peninsula toIslam, severely restricting the reach both of the Byzantine Empire and of its church.Christian missionary activity directed from the capital ofConstantinople did not lead to a lasting expansion of the formal link between the church and the Byzantine emperor, since areas outside the Byzantine Empire's political and military control set up their own distinct churches, as in the case ofBulgaria in 919.^{[citation needed]}

Justinian I, who became emperor in 527, recognized thepatriarchs ofRome,Constantinople,Alexandria,Antioch, andJerusalem as the supreme authorities in the state-sponsoredChalcedonian church apparatus (see thePentarchy). However, Justinian claimed "the right and duty of regulating by his laws the minutest details of worship and discipline, and also of dictating the theological opinions to be held in the Church".^[8][9]

In Justinian's day, the Christian church was not entirely under the emperor's control even in the East: the Oriental Orthodox Churches had seceded, having rejected theCouncil of Chalcedon in 451, and called the adherents of the imperially-recognized church "Melkites", from Syriacmalkâniya ("imperial").^[10][11] InWestern Europe, Christianity was mostly subject to the laws and customs of nations that owed no allegiance to the emperor in Constantinople.^[12] WhileEastern-born popes appointed or at least confirmed by the emperor continued to be loyal to him as their political lord, they refused to accept his authority in religious matters,^[13] or the authority of such a council as the imperially convokedCouncil of Hieria of 754.Pope Gregory III (731–741) was the last Bishop of Rome to ask the Byzantine ruler to ratify his election.^[14][15] With the crowning ofCharlemagne byPope Leo III on25 December 800 asImperator Romanorum, the political split between East and West became irrevocable. Spiritually,Chalcedonian Christianity persisted, at least in theory, as a unified entity until theGreat Schism and its formal division with themutual excommunication in 1054 of Rome and Constantinople. The empire finally collapsed with theFall of Constantinople to the IslamicOttoman Turks in 1453.^[16]

The obliteration of the empire's boundaries byGermanic peoples and an outburst of missionary activity among these peoples, who had no direct links with the empire, and amongPictic andCeltic peoples who had never been part of the Roman Empire, fostered the idea of a universal church free from association with a particular state.^[17] On the contrary, "in the East Roman or Byzantine view, when the Roman Empire became Christian, the perfect world order willed by God had been achieved: one universal empire was sovereign, and coterminous with it was the one universal church";^[18] and the church came, by the time of the demise of the Byzantine Empire in 1453, to merge psychologically with it to the extent that its bishops had difficulty in thinking of Nicene Christianity without an emperor.^[b][21]

The legacy of the idea of a universal church carries on in today's Catholic Church, Eastern Orthodox Church, Oriental Orthodox Churches, and theChurch of the East. Many other churches, such as theAnglican Communion, claimsuccession to this universal church.^{[citation needed]}

Before the end of the 1st century, the Roman authorities recognized Christianity as aseparate religion from Judaism. The distinction, perhaps already made in practice at the time of theGreat Fire of Rome in the year 64, was given official status by the emperorNerva around the year 98 by granting Christians exemption from paying theFiscus Iudaicus, the annual tax upon the Jews.Pliny the Younger, whenpropraetor inBithynia in 103, assumes in his letters toTrajan that because Christians do not pay the tax, they are not Jews.^[22][23][24]

Since paying taxes had been one of the ways that Jews demonstrated their goodwill and loyalty toward the empire, Christians had to negotiate their own alternatives to participating in theimperial cult. Their refusal to worship theRoman gods or to pay homage to theemperor as divine resulted at times in persecution and martyrdom.^[22][23][24]Church FatherTertullian, for instance, attempted to argue that Christianity was not inherently treasonous, and that Christians could offer their own form of prayer for the well-being of the emperor.^[25]

Christianity spread especially in the eastern parts of the empire and beyond its border; in the west it was at first relatively limited, but significant Christian communities emerged inRome,Carthage, and other urban centers, becoming by the end of the3rd century, the dominant faith in some of them. Christians accounted for approximately 10% of the Roman population by 300, according to some estimates.^[26] Christianity then rapidly grew in the 4th century -Rodney Stark estimated that Christians accounted for 56.5% of the Roman population by 350.^[27] According toWill Durant, theChristian Church prevailed overpaganism because it offered a much more attractive doctrine and because the church leaders addressed human needs better than their rivals.^[28]

In 301, theKingdom of Armenia, nominally a Roman client kingdom but ruled by aParthian dynasty,^[29] became the first nation to adopt Christianity as itsstate religion, with the possible exception ofOsroene in 201.^[30]

In 311, with theEdict of Serdica the dying EmperorGalerius ended theDiocletianic Persecution that he is reputed to have instigated, and in 313, EmperorConstantine issued theEdict of Milan, granting to Christians and others "the right of open and free observance of their worship".^[40]

Constantine began to employ Christian symbols such as theChi Rho early in his reign but still encouraged traditional Roman religious practices includingsun worship. In 330, Constantine established the city ofConstantinople as the new capital of the Roman Empire. The city would gradually come to be seen as the intellectual and cultural center of theChristian world.^[41]

Over the course of the4th century the Christian body became consumed by debates surroundingorthodoxy, i.e. which religious doctrines are the correct ones. In the early 4th century, a group inNorth Africa, later calledDonatists, who believed in a very rigid interpretation of Christianity that excluded manywho had abandoned the faith during the Diocletianic Persecution, created a crisis in thewestern empire.^[42]

Asynod was held inRome in 313, followed by another inArles in 314. These synods ruled that the Donatist faith was heresy and, when the Donatists refused to recant, Constantine launched the first campaign of persecution by Christians against Christians, and began imperial involvement in Christian theology. However, during the reign of EmperorJulian the Apostate, the Donatists, who formed the majority party in the Roman province of Africa for 30 years,^[43] were given official approval.^[44]

Christian scholars and populace within the empire were increasingly embroiled in debates regardingchristology (i.e., regarding the nature of theChrist). Opinions ranged from belief that Jesus wasentirely human to belief that he wasentirely divine. The most persistent debate was that between thehomoousian view (the Father and the Son are of one substance), defined at theCouncil at Nicaea in 325 and later championed byAthanasius of Alexandria, and theArian view (the Father and the Son are similar, but the Father is greater than the Son). Emperors thereby became ever more involved with the increasingly divided early Church.^[45]

Constantine backed the Nicene Creed of Nicaea, but was baptized on his deathbed by theEusebius of Nicomedia, a bishop with Arian sympathies. His successorConstantius II supported Arian positions: under his rule, theCouncil of Constantinople in 360 supported the Arian view. After the interlude of EmperorJulian, who wanted to return to the pagan Roman/Greek religion, the west stuck to the Nicene Creed, while Arianism orSemi-Arianism was dominant in the east (under Emperor Valens), until Emperor Theodosius I called theCouncil of Constantinople in 381, which reasserted the Nicene view and rejected the Arian view. This council further refined the definition of orthodoxy, issuing theNicene-Constantinopolitan Creed.^{[citation needed]}

On 27 February of the previous year, Theodosius I established, with theEdict of Thessalonica, the Christianity of theFirst Council of Nicaea as the officialstate religion, reserving for its followers the title of Catholic Christians and declaring that those who did not follow the religion taught byPope Damasus I of Rome andPope Peter of Alexandria were to be calledheretics:^[46]

It is our desire that all the various nations which are subject to our Clemency and Moderation, should continue to profess that religion which was delivered to the Romans by the divine ApostlePeter, as it has been preserved by faithful tradition, and which is now professed by the PontiffDamasus and byPeter, Bishop of Alexandria, a man of apostolic holiness. According to the apostolic teaching and the doctrine of the Gospel, let us believe in theone deity of the Father, the Son and the Holy Spirit, in equal majesty and in a holy Trinity. We authorize the followers of this law to assume the title of Catholic Christians; but as for the others, since, in our judgment they are foolish madmen, we decree that they shall be branded with the ignominious name of heretics, and shall not presume to give to their conventicles the name of churches. They will suffer in the first place the chastisement of the divine condemnation and in the second the punishment of our authority which in accordance with the will of Heaven we shall decide to inflict.

In 391, Theodosius closed all the "pagan" (non-Christian and non-Jewish) temples and formally forbade pagan worship.^[47]

At the end of the 4th century the Roman Empire had effectively split into two parts although their economies and the imperial-recognized church were still strongly tied. The two halves of the empire had always had cultural differences, exemplified in particular by the widespread use of theGreek language in the Eastern Empire and its more limited use in the West (Greek, as well asLatin, was used in the West, but Latin was the spokenvernacular).^{[citation needed]}

By the time Christianity became the state religion of the empire at the end of the 4th century, scholars in the West had largely abandoned Greek in favor of Latin. Even the Church in Rome, where Greek continued to be used in theliturgy longer than in the provinces, abandoned Greek.^[d]Jerome'sVulgate had begun to replace theolder Latin translations of the Bible.

The5th century would see the further fracturing of Christendom. EmperorTheodosius II called two synods inEphesus, one in 431 and one in 449, thefirst of which condemned the teachings of PatriarchNestorius of Constantinople, while the second supported the teachings ofEutyches againstArchbishop Flavian of Constantinople.^[49]

Nestorius taught that Christ's divine and human nature were distinct persons, and henceMary was the mother of Christ but not the mother of God. Eutyches taught on the contrary that there was in Christ only a single nature, different from that of human beings in general. TheFirst Council of Ephesus rejected Nestorius' view, causing churches centered around theSchool of Edessa, a city at the edge of the empire, to break with the imperial church (seeNestorian schism).^[49]

Persecuted within the Roman Empire, many Nestorians fled toPersia and joined theSassanid Church (the futureChurch of the East). TheSecond Council of Ephesus upheld the view of Eutyches, but was overturned two years later by theCouncil of Chalcedon, called by EmperorMarcian. Rejection of the Council of Chalcedon led to the exodus from the state church of the majority of Christians in Egypt and many in the Levant, who preferredMiaphysite theology.^[49]

Thus, within a century of the link established by Theodosius between the emperor and the church in his empire, it suffered a significant diminishment. Those who upheld the Council of Chalcedon became known inSyriac asMelkites, theimperial group, followers of theemperor (in Syriac,malka).^[50] This schism resulted in an independent communion of churches, including the Egyptian, Syrian, Ethiopian and Armenian churches, that is today known asOriental Orthodoxy.^[51] In spite of these schisms, however, the Chalcedonian Nicene church still represented the majority of Christians within the by now already diminished Roman Empire.^[52]

In the 5th century, the Western Empire rapidlydecayed and by the end of the century was no more. Within a few decades,Germanic tribes, particularly theGoths andVandals, conquered the western provinces. Rome was sacked in410 and455, and was to be sacked again in the following century in546.^[39]

By 476, the Germanic chieftainOdoacer had conqueredItaly and deposed the last western emperor,Romulus Augustus, though he nominally submitted to the authority of Constantinople. The Arian Germanic tribes established their own systems of churches and bishops in the western provinces but were generally tolerant of the population who chose to remain in communion with the imperial church.^[39]

In 533, Roman EmperorJustinian in Constantinople launched a military campaign to reclaim the western provinces from the Arian Germans, starting withNorth Africa and proceeding to Italy. His success in recapturing much of the western Mediterranean was temporary. The empire soon lost most of these gains, but held Rome, as part of theExarchate of Ravenna, until 751.

Justinian definitively establishedCaesaropapism,^[53] believing "he had the right and duty of regulating by his laws the minutest details of worship and discipline, and also of dictating the theological opinions to be held in the Church".^[8] According to the entry inLiddell & Scott, the termorthodox first occurs in theCodex Justinianus: "We direct that all Catholic churches, throughout the entire world, shall be placed under the control of the orthodox bishops who have embraced the Nicene Creed."^[54]

By the end of the 6th century the church within the Empire had become firmly tied with the imperial government,^[55] while in the west Christianity was mostly subject to the laws and customs of nations that owed no allegiance to the emperor.^[12]

EmperorJustinian I assigned to five sees, those ofRome,Constantinople,Alexandria,Antioch andJerusalem, a superior ecclesial authority that covered the whole of his empire. TheFirst Council of Nicaea in 325 reaffirmed that the bishop of a provincial capital, the metropolitan bishop, had a certain authority over the bishops of the province.^[56] But it also recognized the existing supra-metropolitan authority of the sees of Rome, Alexandria and Antioch,^[57] and granted special recognition to Jerusalem.^[58][59][60]

Constantinople was added at theFirst Council of Constantinople (381)^[61] and given authority initially only overThrace. By a canon of contested validity,^[62] theCouncil of Chalcedon (451) placedAsia andPontus,^[63] which together made upAnatolia, under Constantinople, although their autonomy had been recognized at the council of 381.^[64][65]

Rome never recognized thispentarchy of five sees as constituting the leadership of the church. It maintained that, in accordance with the First Council of Nicaea, only the three "Petrine" sees of Rome, Alexandria and Antioch had a real patriarchal function.^[66] The canons of theQuinisext Council of 692, which gave ecclesiastical sanction to Justinian's decree, were also never fully accepted by the Western Church.^[67]

Early Muslim conquests of the territories of the patriarchates of Alexandria, Antioch and Jerusalem, most of whose Christians were in any case lost to the orthodox church since the aftermath of the Council of Chalcedon, left in effect only two patriarchates, those of Rome and Constantinople.^[68] In 732, EmperorLeo III'siconoclast policies were resisted byPope Gregory III. The Emperor reacted by transferring to the ecclesiastical jurisdiction of Constantinople in 740 the territories inGreece,Illyria,Sicily andCalabria that had been under Rome (see map), leaving the bishop of Rome with only a minute part of the lands over which the empire still had control.^[69]

The Patriarch of Constantinople had already adopted the title of "ecumenical patriarch", indicating what he saw as his position in theoikoumene, the Christian world ideally headed by the emperor and the patriarch of the emperor's capital.^[70][71] Also under the influence of theimperial model of governance of the state church, in which "the emperor becomes the actual executive organ of the universal Church",^[72] the pentarchy model of governance of the state church regressed to a monarchy of the Patriarch of Constantinople.^[72][73]

TheRashidun conquests began to expand the sway ofIslam beyondArabia in the 7th century, firstclashing with the Roman Empire in 634. That empire and the Sassanid Persian Empire were at that time crippled bydecades of war between them. By the late 8th century theUmayyad caliphate had conquered all ofPersia and much of theByzantine territory includingEgypt,Palestine, andSyria.

Suddenly, much of the Christian world was under Muslim rule. Over the coming centuries the successive Muslim states became some of the most powerful in the Mediterranean world.

Though the Byzantine church claimed religious authority over Christians in Egypt and theLevant, in reality the majority of Christians in these regions were by thenmiaphysites and members of other sects. The new Muslim rulers, in contrast, offered religious tolerance to Christians of all sects. Additionally subjects of the Muslim Empire could be accepted as Muslims simply by declaring a belief in a single deity and reverence for Muhammad (seeshahada). As a result, the peoples of Egypt, Palestine and Syria largely accepted their new rulers and many declared themselves Muslims within a few generations. Muslim incursions later found success in parts of Europe, particularly Spain (seeAl-Andalus).^[74]

During the9th century, the Emperor in Constantinople encouraged missionary expeditions to nearby nations including the Muslim caliphate, and theTurkicKhazars.^{[citation needed]} In 862 he sent SaintsCyril and Methodius toSlavicGreat Moravia. By then most of the Slavic population ofBulgaria was Christian and TsarBoris I himself was baptized in 864.Serbia was accounted Christian by about 870.^[75] In early 867 PatriarchPhotios I of Constantinople wrote that Christianity was accepted by theKievan Rus', which however was definitively Christianized only at the close of the following century.

Of these, the Church in Great Moravia chose immediately to link with Rome, not Constantinople: the missionaries sent there sided with the Pope during thePhotian Schism (863–867).^[76] After decisive victories over the Byzantines atAcheloos andKatasyrtai, Bulgaria declared its church autocephalous and elevated it to the rank of patriarchate, an autonomy recognized in 927 by Constantinople,^[77][78] but abolished by EmperorBasil II Bulgaroktonos (the Bulgar-Slayer) after his 1018 conquest of Bulgaria.

In Serbia, which became an independent kingdom in the early 13th century,Stephen Uroš IV Dušan, after conquering a large part of Byzantine territory in Europe and assuming the title of Tsar, raised the Serbian archbishop to the rank of patriarch in 1346, an autonomy recognized in 1375 by Constantinople,^[79] a rank maintained until after the fall of the Byzantine Empire to the Turks. No Byzantine emperor ever ruled Russian Christendom.

Expansion of the church in western and northern Europe began much earlier, with the conversion of the Irish in the5th century, the Franks at the end of the same century, the Arian Visigoths in Spain soon afterwards, and the English at the end of the6th century. Bythe time the Byzantine missions to central and eastern Europe began, Christian western Europe, in spite of losing most of Spain to Islam, encompassed Germany and part of Scandinavia, and, apart from the south of Italy, was independent of the Byzantine Empire and had been almost entirely so for centuries.

This situation fostered the idea of a universal church linked to no one particular state.^[17] Long before the Byzantine Empire came to an end,Poland also,Hungary and other central European peoples were part of a church that in no way saw itself as the empire's church and that, with theEast-West Schism, had even ceased to be in communion with it.

With the defeat and death in 751 of the lastExarch of Ravenna and the end of the Exarchate, Rome ceased to be part of the Byzantine Empire. Forced to seek protection elsewhere,^[80] the popes turned to theFranks and, with the coronation ofCharlemagne byPope Leo III on 25 December 800, transferred their political allegiance to a rival Roman emperor. Disputes between the see of Rome, which claimed authority over all other sees, and that of Constantinople, which was now without rival in the empire, culminated perhaps inevitably^[81] in mutual excommunications in 1054.

Communion with Constantinople was broken off by European Christians with the exception of those ruled by the empire (including the Bulgarians and Serbs) and of the fledglingKievan or Russian Church, then ametropolitanate of the patriarchate of Constantinople. This churchbecame independent only in 1448, just five years before the extinction of the empire,^[82] after which theTurkish authorities included all their Orthodox Christian subjects of whatever ethnicity in a singlemillet headed by the Patriarch of Constantinople.

The Westerners who set upCrusader states in Greece and the Middle East appointedLatin (Western) patriarchs and other hierarchs, thus giving concrete reality and permanence to the schism.^[83][84][85] Efforts were made in 1274 (Second Council of Lyon) and 1439 (Council of Florence) to restore communion between East and West, but the agreements reached by the participating eastern delegations and by the emperor were rejected by the vast majority of Byzantine Christians.

In the East, the idea that the Byzantine emperor was the head of Christians everywhere persisted among churchmen as long as the empire existed, even when its actual territory was reduced to very little. In 1393, only 60 years before the fall of the capital,Patriarch Antony IV of Constantinople wrote toBasil I of Muscovy defending the liturgical commemoration in Russian churches of the Byzantine emperor on the grounds that he was "emperor (βασιλεύς) and autokrator of the Romans, that isof all Christians".^[19] According to Patriarch Antony, "it is not possible among Christians to have a Church and not to have an emperor. For the empire and the Church have great unity and commonality, and it is not possible to separate them",^[86][87][20] and "the holy emperor is not like the rulers and governors of other regions".^[20][88]

Following the schism between the Eastern and Western churches, various emperors sought at times but without success to reuniteChristendom, invoking the notion of Christian unity between East and West in an attempt to obtain assistance from the pope and Western Europe against the Muslims who were gradually conquering the empire's territory. But the period of the WesternCrusades against the Muslims had passed before even the first of the two reunion councils was held.

Even when persecuted by the emperor, the Eastern Church,George Pachymeres said, "counted the days until they should be rid not of their emperor (for they could no more live without an emperor than a body without a heart), but of their current misfortunes".^[89] The church had come to merge psychologically in the minds of the Eastern bishops with the empire to such an extent that they had difficulty in thinking of Christianity without an emperor.^[21]

In Western Europe, on the other hand, the idea of a universal church linked to the Emperor of Constantinople was replaced by that in which the Roman see was supreme.^[e] "Membership in a universal church replaced citizenship in a universal empire. Across Europe, from Italy to Ireland, a new society centered on Christianity was forming."^[91]

TheWestern Church came to emphasize the termCatholic in its identity, an assertion of universality, while theEastern Church came to emphasize the termOrthodox in its identity, an assertion of holding to the true teachings of Jesus. Both churches claim to be the unique continuation of the previously united state-sanctioned Chalcedonian and Nicene Church, whose core doctrinal formulations have been retained also by many of the churches that emerged from theProtestant Reformation, includingLutheranism andAnglicanism.

• Arian controversy
• Caesaropapism
• Chalcedonian Christianity
• Christian state
• Early Christianity
• History of the Eastern Orthodox Church
• History of Oriental Orthodoxy
• History of Roman Catholicism

• 380s establishments in the Roman Empire
• Christianity in late antiquity
• Christianity in the Byzantine Empire
• Christianity in the Roman Empire

• CS1 Arabic-language sources (ar)
• CS1 German-language sources (de)
• Articles with short description
• Short description is different from Wikidata
• Pages using sidebar with the child parameter
• All articles with unsourced statements
• Articles with unsourced statements from June 2024
• Articles with unsourced statements from December 2012
• CS1 errors: ISBN date
• CS1 maint: multiple names: authors list
• Articles with unsourced statements from January 2023
• Articles containing Tagalog-language text
• Use dmy dates from August 2019