An Ideological History Of Early Christianity [Full Text]
I’m interested in ideologies. How do ideologies grow, how do they organise, and how do they suppress competing ideologies?
The story of Christianity is an epic of ideological warfare: a tiny religious cult that grew to dominate a continent-spanning empire, and then, after the empire’s collapse, built a thousand-year organisation amidst the ruins.
One core assumption I make is that, to understand the actions of agents in history, one must assume that people’s actions were moral and rational within the framework of the ideology within which they operated. If early Christian beliefs were true, it would have been rational and moral for Christians to convert the world to their creed; if Roman beliefs about Christianity were true, it would have been rational and moral for the Romans to uproot Christianity from their society.
If one truly believed that one belonged to the one true faith, living in a fallen world dominated by an evil empire, then devoting one’s life to bringing as many fallen souls as possible back to the one true God would seem to be the right and proper thing to do. Likewise, if one truly believed that one’s glorious civilisation was being corrupted from within by a bizarre, subversive, fanatical cult, then devoting all one’s power to breaking that cult would seem entirely justified and, indeed, the only safe and prudent course of action.
One can only judge others — including others acting in alien cultures long ago — from the framework of some moral code. If one takes for granted that both sides in an ancient, alien conflict were wrong — how is one to know that the modern, seemingly-conventional moral framework one operates within is right?
At the time I initially wrote this article, one thing that struck me (at the time) as highly unexpected was the extreme commitment to intellectual rigour of early Christians. Early Christianity was not a collection of vague platitudes formed by feel-good consensus: early Christians lived every premise of their creed, fought over a single word in their doctrine, and died defending their ideas. Though such an attitude may seem utterly alien to moderns, to those who upheld it, such an attitude was a necessary in the maintenance of absolute devotion to everything good, right and true.
The word ideology was first coined to refer to a proposed science of ideas.  Napoleon Bonaparte was the first to use ideology in the modern, pejorative sense.
The definition of ideology I will use is: a set of ideas that collectively answer fundamental questions of existence, integrated into an internally consistent doctrine, and held by an organised group of followers.
A related, but distinct, concept is that of culture: a culture is a set of ideas that collectively answer fundamental questions of existence, and are shared amongst a self-identified group of people (such as a tribe or nation). The ideas in a culture are not normally integrated into a single doctrine, and may not be universally shared amongst the group. 
Cultures develop naturally as a group of people exchange ideas, whereas ideologies are created consciously by individuals. Cultural groups are defined by ethnicity, location or some other criteria; ideological groups are defined by their ideology.
Cultures and ideologies answer the fundamental questions of reality and morality, e.g. “what is true?”, “what is important?” and “what is good?”. By answering these questions, cultures and ideologies direct the course of human lives; on a grand scale, they shape the course of human history.
Three cultures that are relevant to Christianity’s story are the culture of Greece, the culture of Rome, and the culture of the Jews. The culture of the Jews is also an ideology: specifically, it’s a culture that hardened into an ideology, Judaism.
Stoicism, another influence, is a school of thought, not an ideology. Though Stoicism answered fundamental questions, it didn’t have precise membership requirements: anyone could call themselves a Stoic. Stoic ideas, like the ideas of other Greek philosophical schools, therefore permeated through Greek and Roman culture without an organised movement.
I’m going to cover Christian history from AD 33 to 476, i.e., from the purported death of Jesus to the fall of Rome. This period can be split into three eras.
The first era covers from c. AD 33 to 100, when Christianity was led by the initial disciples, and when the first churches were established.
The second era covers from AD 101 to 324, when Christianity grew from a few thousand to several million followers, and ends with the official end of Roman persecution.
The third era covers from AD 325 to 476 when Christianity became the state religion of the Roman Empire. Ultimately, the Empire split in two, and our story ends with the fall of the Western Empire, and the survival of Christianity amidst the ruins.
Era 1: Origins
Jerusalem and the surrounding province of Judaea have been part of the Roman Empire for over 90 years. For the Jews, though, the Romans are merely the latest empire in a long series of foreign rulers. The bones of Egyptian, Assyrian, Babylonian and Persian conquerers lie buried beneath the ground upon which the Roman legionaries now walk.
Over two centuries prior to the Roman conquest, Alexander the Great had led an army of Greek hoplites southward down the eastern coast of the Mediterranean, taking Judaea — then the Persian province of Yehud — on his way to conquer Egypt, where he celebrated his victory by founding a city in his own name. By AD 33, Alexandria has grown to become the second largest city in the Roman Empire and, with its famous libraries and schools of Greek philosophy, a major cultural and intellectual centre. It’s a true cosmopolis: a world city.
Judaea, then, along with the rest of the Eastern Roman Empire, has known more Greek than Roman influence for the last three centuries. In this part of the Empire, Greek philosophical ideas are widespread, and Greek is more widely spoken than Latin.
Jerusalem, though outshone by nearby Alexandria, is a large and diverse city. Ethiopians, Egyptians and Arabs live alongside the predominant Jewish and Greek communities. Overlooking the city is the Jews’ Second Temple, newly expanded and reconstructed after a project started 46 years earlier by King Herod.
The Temple is a place of pilgrimage for Jews from across the Empire. Pilgrims often arrive by boat in the nearby port town of Jaffa, before embarking on the three-day trek up the road to Jerusalem. When they arrive, they change their Roman and Greek money in the courtyard of the Temple for religiously-approved Jewish and Tyrian coinage.
A few years previously, a charismatic local preacher, enraged by the practice of business in a holy place, had roared with disapproval at the money-changers, flipped over their tables, and chased them out of the Temple with a rope whip.
History knows very little about this man aside from the writings of his own followers. We can surmise that he inspired fanatical devotion, since shortly after his death, a group of them met and agreed that they must spread his ideas across the entire world.
One possible key to Christianity’s unprecedented success is that it was the first missionary religion in Western history. No ideology before it had set its followers the goal of converting all of humanity. What the Romans had conquered with their swords, the Christians planned to conquer with their creed.
These initial followers, the apostles, rapidly dispersed from Jerusalem, aiming to gain converts across the empire.
The apostles were strategic. Rather than focusing only on places near to Jerusalem, they travelled far, establishing Christian communities in major cities across the Mediterranean Basin. The four largest cities of the Empire — Rome, Alexandria, Antioch and Ephesus — all became major early centres of Christianity.
The Greek word ekklesía, assembly, came to be used both for these individual communities and for the global community of Christians.  These individual churches, and the global Church, grew rapidly.
Christianity at first was seen as a Jewish sect: one of many that existed in the highly political atmosphere of Roman-occupied Jerusalem. Ideas of the coming apocalypse were then popular in Jewish culture, and predicted God’s impending destruction of the hated, but seemingly-invincible, Rome.
The book of Revelation, the last book of the Bible, was written around this time and expresses a purely Jewish version of Christianity. No “love thy neighbour” here, only fantasies of divine revenge. God’s angels pour out endlessly imaginative punishments on an unrepentant humanity, and Rome is depicted as Babylon the Great, the Whore of Nations. 666, the number of the beast as defined in Revelation, is likely a numerological reference to Emperor Nero.
The gospels, in contrast, were probably written later and express a mix of Jewish and Greek influences. John’s gospel, for example, begins by equating the Jewish concept of God with the Greek concept of the logos, the transcendent Word. Jesus, as portrayed in the gospels, appears to express Stoic ideas, and recommends the cultivation of serene detachment from worldly cares.
Christianity’s split from Judaism began with Paul of Tarsus, who was the first to propose the idea of converting non-Jews. Paul was both a Jew and a Roman citizen, and saw himself as a bridge between the two worlds.
Paul’s own experiences trying to convert Gentiles had shown him that the Jewish religious requirements, such as male circumcision, were driving away potential new Christians. Paul proposed that most of these requirements be dropped.
In AD 50, the Council of Jerusalem was held by the leaders of Jewish Christianity to discuss Paul’s controversial proposal. Their eventual decision in favour marked the beginning of the official split of Judaism from Christianity.
Paul is arguably the individual most responsible for creating Christianity as an ideology. Not only was he was the key figure in establishing Christianity’s independence from Judaism, he also played a major role in defining early doctrine, and in organising the early Church. Paul has more words in the New Testament than any other Christian figure, Jesus included.
Like a cell split by mitosis, Christianity had developed from an outgrowth of Judaism to an independent entity. Christianity’s independence now brought it to the attention of the pagan Romans.
The Roman attitude towards religion was based on their culture’s need to transform many diverse tribes into a unified society. Though they were tolerant polytheists who would happily let conquered tribes worship their own gods, the Romans also expected good citizens to make frequent public demonstrations of their religious faith, their pietas. Pietas had a wider meaning than English piety, and it wrapped up duty to one’s parents, duty to one’s country, and duty to the gods in a single concept.
The Romans had frequently attempted to deal with social instability by using public religious ceremonies as a means to ensure unity. Christians, as monotheists who refused to worship the Roman gods and who perversely insisted on only worshipping in private, were therefore seen to be flaunting their lack of pietas and appeared to be a destabilising influence.
The Jews, although another troublesome group of monotheists, at least piously followed the ancient God of their distant forefathers. Christianity was something worse: a novel religion, or superstitio (another concept with a wider meaning than the English superstition). Calling Christianity superstitio marked it as a depraved, excessive cult.
The first recorded persecution of Christians happened in AD 64, after the fire in Rome. Rumours were spread blaming Nero, and Nero blamed Rome’s Christians, a number of whom were executed. Christians would continue to be persecuted for the next few centuries, though mostly by the mob, not the state.
A Jewish revolt in AD 70 led to the Romans sacking Jerusalem and destroying the Second Temple. Jews and Christians dispersed, and this was the end of Jerusalem as an early centre of Christianity.
Era one ended with the death of the last of the apostles in AD 101. By this time, over forty churches had been founded, mostly in the Greek-speaking East. With no-one who had known Jesus left alive, authority shifted to the emerging Church organisation.
Era Two: Growth
With the fall of Jerusalem, Christianity was firmly established as a Gentile religion. As of AD 100, it likely numbered less than ten thousand converts.
Christianity’s organisation developed as it grew. The worldwide Church was originally a decentralised organisation; the basic organisational unit of Christianity was the local church, where authority rested with a council of presbyters, literally elders.
By 110, some cities had multiple churches, with the oldest church usually being pre-eminent. The head of this primary church would lead the other churches in the city and was granted the title of bishop, literally overseer. A subordinate role was that of deacon, literally caretaker: a person who catalogued the elders’ decisions and distributed information to members.
Initially these roles were unpaid, part-time positions. With rapid growth the need to instruct new members, and to train new deacons, began to take up more time. The position of elder remained a hands-off, advisory role, but the positions of bishop and deacon eventually became full-time, professional jobs.
As a distributed organisation, the global Church did not yet share a single doctrine. Churches were independent and each maintained its own doctrine and collection of texts. Ideas spread between churches by letter and by regional meetings of bishops.
Over time, a hierarchy of bishops formed; typically the bishop of a provincial capital would lead other bishops in the province. The Bishops of Alexandria and Antioch, the second and third largest cities in the empire, were granted the title of Patriarch in recognition of their importance.
Rome had not yet become a major centre. It’s not clear whether there was a deliberate push from a later faction to centralise Church power in Rome.
The documents that circulated between churches included letters, gospels, personal memoirs, predictions of the coming apocalypse, uplifting advice and practical teachings. At the time there was no uniquely Christian holy book: Christians instead used the Hebrew Bible, i.e., the Old Testament.
Marcion of Sinope was the first to propose compiling a canon of uniquely Christian sacred texts, c. 130. Marcion justified this with his theory that the God of the Hebrews was clearly not Jesus’ God, but a tyrannical usurper, and that Jesus’ teachings offered humanity a path back to the true, secret God. Since the Hebrew Bible was the book of this false God, Christians urgently needed their own book.
Marcion’s theory did not catch on in mainstream Christianity, but it did sow the seeds of a resilient underground movement, Gnosticism. Mainstream Christianity tried to suppress it, but as we’ll see later, never truly managed to wipe it out.
Marcion’s proposal for a Christian canon did catch on, though, and by the end of era two there was a general agreement as to which texts should be considered canon and which should be rejected. The canonical texts later became the books of the New Testament.
With new churches being founded across the empire, and with the increasingly effective organisation ensuring each church continued to gain converts, Christianity sustained its rapid growth. One estimate is that it was growing in numbers by about 40% per decade, a figure similar to that of Mormonism in modern times, and which would imply that there were around two hundred thousand Christians by the year 200. 
The rapid spread of Christianity unnerved the Romans. In 112 Emperor Trajan received a letter from Pliny, a provincial governor, asking for advice on dealing with the Christian cult . Pliny had heard anonymous accusations of depraved Christian practices in his province and had set out to investigate:
“They [the Christians] asserted, however, that the sum and substance of their fault or error had been that they were accustomed to meet on a fixed day before dawn and sing responsively a hymn to Christ as to a god […] Accordingly, I judged it all the more necessary to find out what the truth was by torturing two female slaves who were called deaconesses. But I discovered nothing else but depraved, excessive superstition.”
Pliny later describes Christianity in terms reminiscent of a plague:
“I therefore postponed the investigation and hastened to consult you. For the matter seemed to me to warrant consulting you, especially because of the number involved. For many persons of every age, every rank, and also of both sexes are and will be endangered. For the contagion of this superstition has spread not only to the cities but also to the villages and farms.”
Trajan takes it for granted that Christianity is a problem, but recommends a moderate response: Christians brought before Pliny should be punished, but they can be pardoned if they publicly deny Christ. Furthermore, Pliny should not actively seek out Christians, nor should he listen to anonymous accusations. That would set a “dangerous kind of precedent”.
Most Roman emperors of the 100s and early 200s followed Trajan’s example. Christians frequently faced bottom-up persecutions from the mob, but not top-down persecutions from the state. That would change in 250, during the reign of Emperor Decian.
The background to the Decian persecution was the ongoing crisis faced by the Roman Empire between 230 and 280, and which almost tore it apart.
The crisis began with the appearance of two new military threats: the Sassanid Persian Empire to the east, and the increasingly aggressive barbarians of Germania to the north. An outbreak of plague in 251 further damaged the Empire’s economy and depleted the available manpower for military campaigns.
In the early days of the crisis, Emperor Alexander Severus was forced to cut a deal with the German chieftains. To his troops, this action exposed a shameful lack of manly Roman virtue, and they murdered him. In the chaos and civil war of the following fifty years, twenty-six different men were sworn in as emperor.
With the breakdown in loyalty, the Romans did what they normally did during times of social disunity, and doubled down on pietas. In 250, Emperor Decian ordered every citizen to perform a sacrifice in front of a magistrate, a kind of empire-wide loyalty oath. Those who refused face imprisonment or execution.
By this time there were over one million Christians in the Empire. Many refused to perform the sacrifices, which led to a widespread state persecution of Christians: the first state persecution, in fact, since that of Nero in AD 64.
The Decian persecution was a grave blow to the Church. Many Christians were killed, including major leaders such as the Patriarchs of Alexandria and Antioch, and the Bishop of Rome. Following Decian’s death in battle, the next emperor, Valerian, ordered a new round of persecution in 257.
In 260, however, the Emperor Gallienus inaugurated a policy of tolerance towards Christianity while he focused his efforts on holding the empire together. This period of tolerance lasted for 40 years, and allowed Christianity to continue to grow rapidly throughout the bloody years of crisis.
Ultimately, Rome’s military prowess triumphed, and a succession of strong and decisive leaders was able to reunify the Empire, fight off the barbarians and restore international military supremacy.
By 300 there were over six million Christians in the Empire, representing 10% of its population. Hermits in the deserts of Egypt were forming the first Christian monastic communities, and large churches were being built in Roman cities. Church power was centralising in Rome and the bishop of Rome gained the epithet Father, or Papa — Pope.
Christianity had previously been an urban, lower-class religion, but by this time it was gaining converts in rural areas and among the aristocracy. Christians were filling important positions in the army and the civil bureaucracy. Families were torn apart when people disowned relatives who converted.
Emperor Diocletian, who came to power at the end of the crisis, was a decisive, autocratic ruler. He took the unprecedented step of splitting the Empire in two, then into four, appointing three co-emperors to rule alongside him. He overhauled the bureaucracy and instituted widespread tax reforms. He also launched an all-out attempt to eradicate Christianity from Roman life.
Diocletian issued a series of anti-Christian edicts. His first edict ordered Christian churches to be razed and Christian books to be burned. Christians were forbidden to meet and were stripped of various legal rights; some who opposed were burned alive. His second edict ordered the arrest of all clergy; so many priests were arrested that Roman prisons were forced to release ordinary criminals.
His third edict offered an amnesty, but his fourth edict required all Christians to make a public sacrifice to the Roman gods, on pain of death.
Though these edicts were not enforced at all in some parts of the empire, they were brutally enforced in others. Later Christian writers painted the events as an attempted genocide of Christians, and portrayed Diocletian as a murderous fanatic.
In 305, Diocletian and his right-hand-man, Maximinus, retired, perhaps feeling that they’d managed to break Christianity for good. Christianity survived, however, while the persecution eventually fizzled out. The severity of the persecution had even won Christianity the sympathy of many pagans. A new co-emperor, Licinius, signed the Edict of Milan in 313, declaring the beginning of official tolerance towards Christians.
One of Diocletian’s co-emperors, Constantius, had been consistently opposed to the persecution. His son, Constantine, who succeeded him as co-emperor, was even more sympathetic towards Christianity, and eventually converted.
After Diocletian’s retirement, the system of four co-emperors proved unstable, and the next generation of leaders held a series of civil wars. In 312, Constantine defeated Maxentius in the West, and in 313 Licinius defeated Daia in the East. Constantine and Licinius held an indecisive war in 314, followed by an uneasy truce. In 324, Constantine finally defeated Licinius, and became sole emperor.
After centuries of imperial persecutions, a Christian emperor now ruled Rome.
Era Three: Dominance
Rome didn’t officially convert to Christianity until 380, but from 325 onwards it was ruled by Christian emperors and gradually became a de facto Christian state . (Armenia was the first nation to convert, c. 314, followed by Ethiopia in 325 and Georgia in 337).
Though Rome was sacked by barbarians in 410, it’s a mistake to see the 300s as a period of constant decline. By the time Constantine came to power, Rome had partially recovered from the crisis of the mid-200s, and it appeared that Diocletian’s decisive reforms had begun to turn things around. Still, the economy in some provinces had been wrecked; Gaul and Britain were already shifting to a feudal system of entirely local trade.
To Diocletian, it had seemed that Christianity was infiltrating every Roman institution, and uprooting the pagan faith that held Roman society together. Still, it couldn’t be denied that the Church was a stable, unified, centralised organisation, with a reach spanning the entire empire. Constantine’s plan was to convert the Empire to Christianity, unite the Church with the Roman state, and use Christianity as a force for social unity.
First, though, Christianity itself had to become unified.
During era two, the Church had slowly standardised on a single doctrine. Two new terms came into use: orthodoxy, right-thought, and heresy, choice, i.e. freely chosen ideas . Right-thinking orthodox bishops had been persecuting free-thinking heretics with as much gusto as earlier pagan emperors had shown when persecuting Christians.
Over the centuries, many independent intellectual movements had arisen within the decentralised Church, been denounced as heresies by the emerging orthodoxy, and were squashed before they could organise into independent ideologies. Two heresies, though, arguably survived long enough to form ideologies in their own right.
The first was Gnosticism, which we encountered earlier, an ideology that grew outside of orthodoxy. The second was Arianism, an ideology that split orthodoxy from within.
Gnosticism, a motley collection of secret societies and cults, clashed with orthodoxy over the authority of the Church. In era one, authority rested with the original apostles. From era two onwards, authority was based on a person’s degrees of separation from the apostles. If a person had been taught by someone who’d been taught by an apostle — who had himself been taught by Jesus — that person was worth listening to. The bishops of the Church claimed to be the main inheritors of this authority and, therefore, of Christian teachings.
The Gnostics subverted this idea and claimed that the apostles had given them secret teachings. They also maintained their own collection of sacred texts: the Gnostic gospel of Thomas, for example, presents a Jesus who resembles a Zen master or Hindu sage. Gnostic comes from gnosis, knowledge, and the Gnostics held that their secret knowledge was far more authoritative than any doctrine preached by the Church.
The Arian heresy, in contrast, started over an intellectual dispute. The famous catechetical school in Alexandria was a centre for both Christian and Greek thought, a place where ideas from both traditions could be debated and exchanged. A fairly secular intellectual hub, Alexandria proved to be a “safe space” for the development of ideas that would have been denounced as heretical elsewhere.
Alexandria’s Christian thinkers, trained in Greek philosophy, had been slowly working through the logical implications of Christian doctrine. In doing so, they exposed some seeming paradoxes. Arianism arose from the following question: if Christ is both God and the Son of God, does that imply that God is His own Son?
The Arians, named after their leader Arius, said no. God obviously can’t be his own Son, and so Christ cannot himself be God: he was just the first and greatest creation of God.
The other side, best described as Trinitarians, said yes. They attempted to resolve the paradox by developing the idea of the Trinity, which held that God consisted of three persons yet was still somehow a single being. 
This seemingly minor conflict had big ramifications for Christianity. Trinitarianism maintained the status of Christ at the cost of logic, arguing that the nature of God was ultimately beyond human understanding. Arianism was arguably the more straightforward position, but it lowered the status of Christ, and Trinitarians saw this as blasphemy.
In 325, Constantine ordered a global meeting of Christians to resolve the dispute, to be held in Nicaea in northern Turkey. The Council of Nicaea was attended by about three hundred bishops and possibly over a thousand deacons and presbyters: one famous delegate was Saint Nicholas, the original Father Christmas. Arius led the debate for the Arian faction, and another Alexandrian, Athanasius, represented the Trinitarians.
It was an an intense and emotional debate; Saint Nicholas slapped Arius in the face during one particularly heated argument. Still, despite being a charismatic speaker and learned philosopher, Arius ultimately lost. Even the small number of bishops who had initially agreed with him switched to side with Athanasius, and in the end only two bishops voted in Arius’ favour. Arianism was condemned as a heresy, and Arius was excommunicated. Arians were exiled, and their books were burned.
The Council of Nicaea issued a creed, the Nicene Creed, declaring Trinitarianism as the orthodox Christian position. (The debate between the two factions had ultimately come down to a single word within the creed — homoousios vs homoiousios, i.e. whether Christ was of the same-substance as the Father or merely of a similar-substance).
Arianism, however, proved to have a wider following than Nicaea had suggested, and Christianity remained divided.
In 330, Constantine moved the imperial capital from Rome to his new city, Constantinople, modern day Istanbul. This move to the wealthy and populous East marked a recognition of the relative decline of the West.
Another exiled Arian, Eusebius of Nicomedia, later convinced Constantine to let him return, and he then moved to Constantinople to join the imperial court. A skilled politician, Eusebius swiftly began making allies within the court and turning the emperor against Trinitarians.
This was a major shift in Arianism’s fortunes. Eusebius eventually managed to have the leaders of the Trinitarian faction exiled, Athanasius included.
Constantine died in 337. After his death, the empire became divided once again. Eusebius, by this time Patriarch of Constantinople, persuaded the new Eastern Emperor, Constantius II, to convert the empire to Arianism.
Eusebius also sent a Gothic monk, Ulfilas, on a mission north of the Danube to convert the Gothic tribes there to Arian Christianity; Ulfilas’ success would later have significant consequences.
Athanasius was allowed to return to Alexandria after Constantine’s death, but in 338 was exiled again by Constantius, and over the course of his life was exiled a total of five times under four different emperors: many of these years were spent hiding in the desert monasteries of Egypt. His curmudgeonly refusal to bow to state pressure earned him the epithet Athansius contra mundum, Athanasius against the world.
Over the next four decades, Trinitarianism remained predominant in the Western Empire and in influential Alexandria; Arianism became predominant in the Eastern Empire and in the imperial court, and gained a foothold in the West under Constantius, as the Arian-dominated state brutally attempted to suppress Trinitarianism.
The doctrinal differences between Arianism and Trinitarianism helped define them as political forces. As the arguably simpler doctrine, easier to sell to those not versed in the details of Christian theology, Arianism was a better fit with Constantine’s plans to unite Church and state. Trinitarianism, in contrast, by making the central concept of Christianity a holy mystery, something to be accepted on faith alone, served to reinforce the authority of the Church.
Trinitarianism finally became dominant at the court in the same manner Arianism had — through personal influence over the emperor. The wife of emperor Theodosius was a staunch Trinitarian, and her influence inspired him to issue the Edict of Thessalonica in 381, banning pagan practices and formally establishing Christianity — specifically, Trinitarian Christianity — as the state religion of the Empire.
From 380 onwards, the situation in the Western Empire deteriorated rapidly.
Population movements far away in Central Asia led to increased numbers of barbarians appearing along the Empire’s borders. The Visigoths, fleeing the Ostrogoths, who were themselves fleeing the Huns, were allowed to settle in the Eastern Empire, but rebelled in 378.
There was a civil war between East and West; the leader of the Visigoths, Alaric I, took advantage of Rome’s internal conflict and started another rebellion. With the Rhine border stripped of troops, Vandals, Alains and Suevi invaded Gaul.
The East, struggling to survive itself, could not spare the forces to save the West. Alaric I and his men sacked Rome in 410.
The Western Empire limped on in some form for several decades, but was gradually dismembered by barbarian tribes, with the last emperors being little more than the puppets of barbarian kings. In 476, Odoacer, a Germanic chieftain, killed the last Western emperor and became the first King of Italy, marking the symbolic end of the Western Roman Empire.
476 marks the traditional beginning of the Early Middle Ages in Europe; an era sometimes described, due to the scant records of this time, as the Dark Ages. What did the world of 476 look like?
The former territories of the Western Empire had been divided into small Germanic kingdoms, while the Eastern Empire had survived, and would endure for almost a millennia as a Greek-speaking, Christian state.
Alexandria was no longer an intellectual centre, its temples and libraries likely destroyed during the persecution of paganism in 391.
Though the Western Empire was gone, Rome, the eternal city, still stood, and the Bishop of Rome still claimed the title Pope and supreme authority over the Church. Christians in the Eastern Empire, however, saw him as merely one of five primary bishops, and this dispute would later develop into the split between the Roman Catholic and Eastern Orthodox Churches.
Arianism, brought to the Goths by Ulfilas, flourished amongst the barbarians. The Franks in Gaul, the Visigoths in Spain, and the Ostrogoths in the Balkans built Arian churches and maintained a separate Arian hierarchy of priests; Arianism would not be fully suppressed by the Catholic Church until the 600s.
Two final strands of our story epitomise the complicated role of Christianity in the history of Western thought.
Christian monastic communities, modelled after those tha had hosted Athanasius in the Egyptian desert, spread into Europe via North Africa and the Middle East. Christian monks would be key in preserving Classical ideas through the Dark Ages, squirrelling away Greek and Roman texts in their monasteries. Hundreds of years later, these monasteries would develop into a network of knowledge-sharing institutions: the medieval universities.
Gnosticism, suppressed by seemingly never eradicated, disappeared from history during the Dark Ages; hundreds of years later, it would reappear in Bulgaria and from there spread into Western Europe in the form of Catharism. The Catholic Church would ultimately root it out by by establishing that notorious group of heresy-squashing organisations: the medieval inquisitions.
The University, the Monastery and the Inquisition: symbols of Christianity as the creator, preserver and destroyer of ideas.
I earlier defined ideologies as having two essential features: an internally consistent doctrine, and an organised group of followers. These two features reinforce each other: the doctrine decrees the structure, membership requirements and leadership of the organisation; the organisation develops, maintains and promotes the doctrine.
How did Christianity develop into an ideology?
It began as simply a movement within Judaism: an informal group of followers sharing the teachings of Jesus. The Council of Jerusalem defined it as an independent entity, and from then on, its organisation and doctrine developed in parallel.
The organisation developed a cellular structure of independent churches, then structure within churches, and then a hierarchical structure between churches, and finally central nodes in Rome, Antioch and Alexandria. The doctrine developed via messages passed between churches, then debate on which messages contained valid information, then organisational suppression of invalid information, and then integration and compilation of officially-authorised information.
After the Council of Nicaea, the Church authorised a proto-Bible, which justified the authority of the Church. Thus Church and Bible formed a self-maintaining system and, from then on, remained remarkably consistent.
The rise of Christianity, therefore, is a deep, rich, complex example showcasing how a particular set of ideas can spread in a society — the ur-pattern, perhaps, as Christianity had a solid claim to be — at the time of its genesis — one-of-a-kind in human history. In later centuries, the spread of ideas that made up the world-historical cultural movement known as the Enlightenment — or, in contrast, the political-ideological movement known as Communism, which dominated three continents — represented alternative patterns of cultural change. The flows and interconnections of human consciousness that constitute cultural history, though challenging to trace out and understand, are therefore ripe for integrated analysis.
 Yes, this is narrower than the standard definition of culture. I’ll justify the reasons for my revised definition in a future post.
 An alternative Greek phrase, Kyriakós oíkos, House of the Lord, entered Old English as cirice and is the origin of our modern word church.
 Rodney Stark, https://books.google.co.th/books?id=HcFSaGvgKKkC&pg=PA6
 With one exception: Julian the Apostate, a follower of Neoplatonism who ruled for less than two years, and who was a rather interesting character: https://en.wikipedia.org/wiki/Julian_I
 Another great term, heresiarch, meaning the founder or leader of a heretical movement, has sadly fallen out of common use.
 Trinitarians were careful to argue that God did not consist of three parts, which was another heresy, partialism. Nor did He possess three different aspects, which was yet another heresy, modalism. The nature of God was simply a holy mystery, inconceivable to humans.
It’s actually hard to explain the Trinity without accidentally expounding some ancient heresy, as this video humorously demonstrates: https://www.youtube.com/watch?v=KQLfgaUoQCw
The two best general online resources for early Christianity I found were:
The Catholic Encyclopedia (pro-Christian): http://www.newadvent.org/cathen/
Early Christian History (neutral to mildly anti-Christian): http://www.earlychristianhistory.info/
Other useful resources:
On the History of Early Christianity, Frederick Engels, https://www.marxists.org/archive/marx/works/1894/early-christianity/
Pliny and Trajan on Christians, http://faculty.georgetown.edu/jod/texts/pliny.html
“What if Arianism had won?”, https://www.youtube.com/watch?v=sa_3a0bT_98
How Arianism Almost Won, https://www.christianhistoryinstitute.org/magazine/article/how-arianism-almost-won/
Documents of the Early Arian Controversy, http://www.fourthcentury.com/index.php/urkunde-chart-opitz/
Those without a spare few months to read Gibbon’s Decline and Fall of the Roman Empire may enjoy this selection of choice quotes: http://www.his.com/~z/gibbon.html