Having searched and failed to find a good map of the expansion of Christianity (most maps focus on only Christianity’s westward expansion, completely neglecting the fact that early Christianity was tri-continental,) I wanted to gift you with one. But Photoshop is not my friend today, so this may take a while.
In the meanwhile, I’m going to writeup my research notes on the spread of Christianity:
One of the things people tend to forget (or else never realize,) is that Christianity was once common throughout the Middle East, North Africa, and the Horn of Africa. These regions are now heavily Muslim, but of course Islam didn’t exist prior to the early 600s. So for about 500 years–half a millennium–Christianity was the hot new monotheism in town.
(Indeed, while we moderns tend to think of “religions” as well-defined, distinct belief systems, I have no reason to think that 7th century Middle Eastern peasants saw it that way. Islam built and expanded upon existing Jewish and Christian beliefs/rituals/texts, and could be reasonably thought, like Mormonism, as an offshoot of them. But for better or worse, Islam has left the Christian family tree, and so will not be considered here.)
Christianity began, of course, among Jewish people of Judah–modern Israel, Palestine, and Jordan. It spread easily among Semitic-speaking peoples, across major trade routes and through local empires, such as Assyria, Rome, and Phoenicia. It spread quickly to Iraq, Turkey, Persia, Malta, Greece, Armenia, Egypt, Georgia, the Caucasus, Balkans, India, North Africa, Italy, Ethiopia, Sudan, Arabia, etc.
In 44 AD, legend has it that St. James was preaching in Spain.
45 AD, mission of Barnabas and Paul to Cyprus and modern Turkey
47 AD, The Church of the East, aka the Nestorian Church, is created by Saint Thomas. It spreads throughout the Sasanian (aka Iranian) empire, eventually reaching Mongolia. Genghis Khan’s own family were Nestorian Christians.
50-53 AD, Paul’s mission to Greece, Macedonia, etc.
In 52 AD, legend states that St. Thomas reached India.
59, Paul in Malta
60 Paul in Rome
72 Martyrdom of St. Thomas in Mylapore, India
By the end of the first century, we have the beginnings of the Western (Roman) church; the Orthodox Church (I think); the Syrian church with its offshoot the Nestorians, who spread through the Middle East and central Asia; the Coptic church in Egypt; the Ethiopian church; and the St. Thomas Christians in India. Some notes:
Coptic history is part of history of Egypt that begins with the introduction of Christianity in Egypt in the 1st century AD during the Roman period, and covers the history of the Copts to the present day.
The first Christians in Egypt were mainly Alexandrian Jews such as Theophilus, whom Saint Luke the Evangelist addresses in the introductory chapter of his gospel. When the Church of Alexandria was founded by Saint Mark  during the reign of the Roman emperor Nero, a great multitude of native Egyptians (as opposed to Greeks or Jews) embraced the Christian faith.
Christianity spread throughout Egypt within half a century of Saint Mark’s arrival in Alexandria as is clear from the New Testament writings found in Bahnasa, in Middle Egypt, which date around the year 200 AD, and a fragment of the Gospel of John, written in Coptic, which was found in Upper Egypt and can be dated to the first half of the 2nd century. In the 2nd century, Christianity began to spread to the rural areas, and scriptures were translated into the local language, namely Coptic.
The Arab Muslim conquest of Egypt took place in 639. Despite the political upheaval, Egypt remained a mainly Christian land, although the gradual conversions to Islam over the centuries changed Egypt from a mainly Christian to a mainly Muslim country by the end of the 12th century.
Ethiopia and Armenia apparently compete for the title of “first nation to accept Christianity.” Wikipedia notes:
Pinpointing a date as to when Christianity emerged in Ethiopia is uncertain. The earliest and best known reference to the introduction of Christianity is in the New Testament (Acts 8:26-38) when Philip the Evangelist converted an Ethiopian court official in the 1st Century AD. … Judaism was practiced in Ethiopia long before Christianity arrived and the Ethiopian Orthodox Bible contains numerous Jewish Aramaic words. The Old Testament in Ethiopia may be a translation of the Hebrew with possible assistance from Jews. …
With the emergence of Islam in the 7th century, Ethiopia’s Christians became isolated from the rest of the Christian world. The head of the Ethiopian church has been appointed by the patriarch of the Coptic church in Egypt, and Ethiopian monks had certain rights in the church of the Holy Sepulchre in Jerusalem. Ethiopia was the only region of Africa to survive the expansion of Islam as a Christian state.
Christianity may have reached India in 52 AD. Wikipedia states:
The Saint Thomas Christians or Thomas Christians, also called Syrian Christians or Nasrani, are a community of Christians from Kerala, India, who trace their origins to the evangelistic activity of Thomas the Apostle in the 1st century.
According to tradition, St. Thomas, one of the 12 apostles, came to Muziris on the Kerala coast in AD 52 which is in the present day Pattanam, Kerala. … The Cochin Jews are known to have existed in Kerala in the 1st century AD, and it was possible for an Aramaic-speaking Jew such as St. Thomas from Galilee to make a trip to Kerala in the 1st century; however, there is no contemporary evidence for this incident. The earliest known source connecting the apostle to India is the Acts of Thomas, likely written in the early 3rd century, perhaps in Edessa.
An organised Christian presence in India dates to the arrival of East Syrian settlers and missionaries from Persia, members of what would become the Church of the East, in around the 3rd century. …
Some contact and transmission of knowledge of the Saint Thomas Christians managed to reach the Christian West, even after the rise of the Islamic empires. … During the Crusades, distorted accounts of the Saint Thomas Christians and the Nestorian Church gave rise to the European legend of Prester John.
Anyway, you’ve probably heard of the Copts and maybe the Ethiopians, but the Nestorians are really the big story.
The Church of the East… also known as the Nestorian Church,[note 1] is a Christian church within the Syriac tradition of Eastern Christianity. It was the Christian church of the Sasanian Empire, and quickly spread widely through Asia. …
Christians were already forming communities in Assyria (Athura) as early as the first century, when it was part of the Parthian Empire. By the third century, the area had been conquered by the Persian Sasanian Empire (becoming the province of Assuristan), and there were significant Christian communities in northern Mesopotamia, Elam, and Fars.
By the end of the 5th century and the middle of the 6th, the area occupied by Nestorians included “all the countries to the east and those immediately to the west of the Euphrates”, including Persia, Egypt, Syria, Arabia, Socotra, Mesopotamia (Assyria and Babylonia), Media, Bactria, Hyrcania, and India; and possibly also to places called Calliana, Male, and Sielediva (Ceylon). Beneath the Patriarch in the hierarchy were nine metropolitans, and clergy were recorded among the Huns, in Persarmenia, Media, and the island of Dioscoris in the Indian Ocean. …
In the 13th and 14th centuries the church experienced a final period of expansion under the Mongol Empire, where influential Nestorian Christians sat in the Mongol court….
Several Mongol tribes had already been converted by Nestorian missionaries in the 7th century, and Christianity was therefore a major influence in the Mongol Empire.Genghis Khan was a shamanist, but his sons took Christian wives from the powerful Kerait clan, as did their sons in turn. During the rule of Genghis’s grandson, the Great Khan Mongke, Nestorian Christianity was the primary religious influence in the Empire, and this also carried over to Mongol-conquered China, during the Yuan Dynasty. It was at this point, in the late 13th century, that the Church of the East reached its greatest geographical extent. But Mongol power was already waning, as the Empire dissolved into civil war, and it reached a turning point in 1295, when Ghazan, the Mongol ruler of the Ilkhanate, made a formal conversion to Islam when he took the throne. …
From its peak of geographical extent, the church experienced a rapid period of decline starting in the 14th century, due in large part to outside influences. The Mongol Empire dissolved into civil war, the Chinese Ming dynasty overthrew the Mongols (1368) and ejected Christians and other foreign influences from China, and many Mongols in Central Asia converted to Islam. The Muslim Mongol leader Timur (1336–1405) nearly eradicated the remaining Christians in Persia; thereafter, Nestorian Christianity remained largely confined to Upper Mesopotamia and to the Malabar Coast of India.
177 AD: Persecution in Lyon, France
Manichaeism is an interesting digression in this tale. It was a religious movement founded by the Iranian prophet Mani, who lived c. 216-276. Like Islam, Manichaeism argued that earlier religions (ie, Christianity, Judaism, Zoroastrianism, Buddhism) were incomplete. Wikipedia states:
Manichaeism was quickly successful and spread far through the Aramaic–Syriac speaking regions. It thrived between the third and seventh centuries, and at its height was one of the most widespread religions in the world. Manichaean churches and scriptures existed as far east as China and as far west as the Roman Empire. It was briefly the main rival to Christianity in the competition to replace classical paganism. Manichaeism survived longer in the east than in the west, and it appears to have finally faded away after the 14th century in southern China contemporary to the decline in China of the Church of the East during the Ming Dynasty. While most of Manichaeism’s original writings have been lost, numerous translations and fragmentary texts have survived. …
Mani began preaching at an early age and was possibly influenced by contemporary Babylonian-Aramaic movements such as Mandaeanism, and Aramaic translations of Jewish apocalyptic writings similar to those found at Qumran (such as the book of Enoch literature), and by the Syriac dualist-gnostic writer Bardaisan (who lived a generation before Mani). With the discovery of the Mani-Codex, it also became clear that he was raised in a Jewish-Christian baptism sect, the Elcesaites, and was influenced by their writings as well. …
Manichaeism spread with extraordinary speed through both the east and west. It reached Rome through the apostle Psattiq by a.d. 280, who was also in Egypt in 244 and 251. It was flourishing in the Fayum area of Egypt in 290. Manichaean monasteries existed in Rome in 312 during the time of the Christian Pope Miltiades.
In 291, persecution arose in the Persian empire with the murder of the apostle Sisin by Bahram II, and the slaughter of many Manichaeans. In 296, Diocletian decreed against the Manichaeans: “We order that their organizers and leaders be subject to the final penalties and condemned to the fire with their abominable scriptures”, resulting in martyrdom for many in Egypt and North Africa (see Diocletian Persecution). By 354, Hilary of Poitiers wrote that the Manichaean faith was a significant force in southern Gaul. In 381 Christians requested Theodosius I to strip Manichaeans of their civil rights. He issued a decree of death for Manichaean monks in 382.
Augustine of Hippo (354–430) converted to Christianity from Manichaeism, in the year 387. This was shortly after the Roman Emperor Theodosius I had issued a decree of death for all Manichaean monks in 382 and shortly before he declared Christianity to be the only legitimate religion for the Roman Empire in 391. Due to the heavy persecution, the religion almost disappeared from western Europe in the 5th century and from the eastern portion of the empire in the 6th century. According to his Confessions, after nine or ten years of adhering to the Manichaean faith as a member of the group of “hearers”, Augustine became a Christian and a potent adversary of Manichaeism …
Some modern scholars have suggested that Manichaean ways of thinking influenced the development of some of Augustine’s ideas, such as the nature of good and evil, the idea of hell, the separation of groups into elect, hearers, and sinners, and the hostility to the flesh and sexual activity.
301 AD, Christianity becomes state religion of Armenia
319: State religion of Georgia
325: State religion of Aksumite Empire
330: State religion of Axum, (Ethiopia)
354 – 430 AD, life of St. Augustine of Hippo, modern day Algeria (Augustine was ethnically Berber, but spoke Latin and of course a member of the Roman empire.)
380: official religion of Rome
596 AD: Gregorian Mission to Britain
7th-9th centuries: Conversion of the Germanic tribes
In the 7th century the Nestorians reached China, but in 9th century, the Tang Emperor persecuted all foreign religions, including Buddhists, Manichaens, and Nestorians.
740 AD: Conversion of the Khazars to Judaism;
927: Conversion of Bulgaria to Christianity
965: Conversion of the Khazars to Islam
988: Conversion of the Kievan Rus (Russia) to Christianity
Well, I hope you have a lovely Christmas/ Channukkah / whatever you celebrate.