Christianity began as a Second Temple Judaic sect in the 1st century in the Roman province of Judea. Jesus’ apostles and their followers spread around Syria, the Levant, Europe, Anatolia, Mesopotamia, Transcaucasia, Egypt, and Ethiopia, despite initial persecution.
Christianity developed during the 1st century CE as a Jewish Christian sect of Second Temple Judaism. An early Jewish Christian community was founded in Jerusalem under the leadership of the Pillars of the Church, namely James the Just, the brother of the Lord, Saint Peter, and John. They had known Jesus, and, according to Paul, the arisen Christ had first appeared to James and Peter.
Jewish Christianity soon attracted Gentile God-fearers, posing a problem for its Jewish religious outlook, which insisted on close observance of the Jewish commands. Paul the Apostle solved this by insisting that salvation by faith in Christ, and participation in His death and resurrection, sufficed.
At first he persecuted the early Christians, but after a conversion experience he preached to the gentiles, and is regarded as having had a formative effect on the emerging Christian identity as separate from Judaism. Eventually, his departure from Jewish customs would result in the establishment of Christianity as an independent religion.
This formative period was followed by the early bishops, whom Christians consider the successors of Christ’s apostles. From the year 150, Christian teachers began to produce theological and apologetic works aimed at defending the faith. These authors are known as the Church Fathers, and the study of them is called patristics.
Christianity spread to Aramaic-speaking peoples along the Mediterranean coast and also to the inland parts of the Roman Empire and beyond that into the Parthian Empire and the later Sasanian Empire, including Mesopotamia, which was dominated at different times and to varying extents by these empires.
The presence of Christianity in Africa began in the middle of the 1st century in Egypt and by the end of the 2nd century in the region around Carthage. Mark the Evangelist is claimed to have started the Church of Alexandria in about 43 CE; various later churches claim this as their own legacy, including the Coptic Orthodox Church of Alexandria.
King Tiridates III made Christianity the state religion in Armenia between 301 and 314, thus Armenia became the first officially Christian state. It was not an entirely new religion in Armenia, having penetrated into the country from at least the third century, but it may have been present even earlier.
Constantine I was exposed to Christianity in his youth, and throughout his life his support for the religion grew, culminating in baptism on his deathbed. During his reign, state-sanctioned persecution of Christians was ended with the Edict of Toleration in 311 and the Edict of Milan in 313.
At that point, Christianity was still a minority belief, comprising perhaps only five percent of the Roman population. Influenced by his adviser Mardonius, Constantine’s nephew Julian unsuccessfully tried to suppress Christianity.
On 27 February 380, Theodosius I, Gratian, and Valentinian II established Nicene Christianity as the State church of the Roman Empire. As soon as it became connected to the state, Christianity grew wealthy; the Church solicited donations from the rich and could now own land.
Constantine was also instrumental in the convocation of the First Council of Nicaea in 325, which sought to address Arianism and formulated the Nicene Creed, which is still used by the Catholic Church, Eastern Orthodoxy, Anglican Communion, and many Protestant churches.
Nicaea was the first of a series of ecumenical councils, which formally defined critical elements of the theology of the Church, notably concerning Christology. The Church of the East did not accept the third and following ecumenical councils and is still separate today by its successors (Assyrian Church of the East).
In terms of prosperity and cultural life, the Byzantine Empire, also referred to as the Eastern Roman Empire or Byzantium, was one of the peaks in Christian history and Christian civilization, and Constantinople remained the leading city of the Christian world in size, wealth, and culture.
There was a renewed interest in classical Greek philosophy, as well as an increase in literary output in vernacular Greek. Byzantine art and literature held a preeminent place in Europe, and the cultural impact of Byzantine art on the West during this period was enormous and of long-lasting significance.
The later rise of Islam in North Africa reduced the size and numbers of Christian congregations, leaving in large numbers only the Coptic Church in Egypt, the Ethiopian Orthodox Tewahedo Church in the Horn of Africa and the Nubian Church in the Sudan (Nobatia, Makuria and Alodia).
A coin dated to 324 shows that Ethiopia was the second country to officially adopt Christianity (after Armenia did so in 301), although the religion may have been at first confined to court circles; it was the first major power to do so.
Around the 8th century BC, a kingdom known as Dʿmt was established in Tigray, in northern Ethiopia, and Eritrea. The polity’s capital was located at Yeha, in northern Ethiopia. Most modern historians consider this civilization to be a native Ethiopian one, although Sabaean-influenced because of the latter’s hegemony of the Red Sea.
Other scholars regard Dʿmt as the result of a union of Afroasiatic-speaking cultures of the Cushitic and Semitic branches; namely, local Agaw peoples and Sabaeans from South Arabia. However, Ge’ez, the ancient Semitic language of Ethiopia, is thought to have developed independently from Sabaean, one of the South Semitic languages.
As early as 2000 BC, other Semitic speakers were living in Ethiopia and Eritrea where Ge’ez developed. Sabaean influence is now thought to have been minor, limited to a few localities, and disappearing after a few decades or a century. It may have been a trading or military colony in alliance with the Ethiopian civilization of Dʿmt or some other proto-Aksumite state.
After the fall of Dʿmt during the fourth century BC, the Ethiopian plateau came to be dominated by smaller successor kingdoms. In the first century AD, the Kingdom of Aksum emerged in what is now Tigray and Eritrea.
According to the medieval Book of Aksum, the kingdom’s first capital, Mazaber, was built by Itiyopis, son of Cush. Aksum would later at times extend its rule into Yemen on the other side of the Red Sea. The Persian religious figure Mani listed Aksum with Rome, Persia, and China as one of the four great powers of his era, during the 3rd century.
Around 316 AD, Frumentius and his brother Edesius from Tyre accompanied their uncle on a voyage to Ethiopia. When the vessel stopped at a Red Sea port, the natives killed all the travellers except the two brothers, who were taken to the court as slaves. They were given positions of trust by the monarch, and they converted members of the royal court to Christianity. Frumentius became the first bishop of Aksum.