The largest and oldest is the Ethiopian Orthodox Tewahedo Church (in Amharic: የኢትዮጵያ ኦርቶዶክስ ተዋሕዶ ቤተክርስትያን Yäityop'ya ortodoks täwahedo bétäkrestyan) is an Oriental Orthodox church in Ethiopia that was part of the Coptic Orthodox Church until 1959, when it was granted its own Patriarch by Coptic Orthodox Pope of Alexandria and Patriarch of All Africa Cyril VI.
The only pre-colonial Christian church of Africa (alongside the now independent Eritrean Orthodox Tewahedo Church), the Ethiopian Church has a membership of between 40 and 45 million, and is thus the largest of all Oriental Orthodox churches.
The earliest and best known reference to the introduction of Christianity is in the New Testament (Acts -38) when Philip the Evangelist converted an Ethiopian court official in the 1st Century AD.
Scholars, however, argue that Ethiopian (which in Greek means "burnt face") was a common term used for black Africans, and that the Queen Candace served by this official actually ruled in nearby Nubia (modern Sudan).
Next in size are the various Protestant congregations, who include 13.7 million Ethiopians.
The largest Protestant group is the Ethiopian Evangelical Church Mekane Yesus, with about 5 million members.
Although Christianity existed long before the rule of King Ezana the Great of the Kingdom of Axum, the religion took a strong foothold when it was declared a state religion in 330 AD.
Pinpointing a date as to when Christianity emerged in Ethiopia is uncertain.
Christianity in Ethiopia dates to the 1st century AD, arguably the first nation in the world to accept Christianity (the other nation to debate this being Armenia) and this long tradition makes Ethiopia unique amongst sub-Saharan African countries.
Christianity in this country is divided into several groups.