The Ethiopian Church claims its earliest origins from the royal official said to have been baptized by Philip the Evangelist (not to be confused with Philip the Apostle), one of the seven deacons:
- Then the angel of the Lord said to Philip, Start out and go south to the road that leads down from Jerusalem to Gaza. So he set out and was on his way when he caught sight of an Ethiopian. This man was a eunuch, a high official of the Kandake (Candace) Queen of Ethiopia in charge of all her treasure. (Acts, 8:27)
The passage continues by describing how Philip helped the Ethiopian treasurer understand a passage from Isaiah that the Ethiopian was reading. After the Ethiopian received an explanation of the passage, he requested that Philip baptize him, and Philip did so. The Ethiopic version of this verse reads "Hendeke" (ህንደኬ); Queen Gersamot Hendeke VII was the Queen of Ethiopia from ca. 42 to 52.
Orthodox Christianity became the established church of the Ethiopian Axumite Kingdom under king Ezana in the 4th century through the efforts of a Syrian Greek named Frumentius, known in Ethiopia as Abba Selama, Kesaté Birhan ("Father of Peace, Revealer of Light"). As a youth, Frumentius had been shipwrecked with his brother Aedesius on the Eritrean coast. The brothers managed to be brought to the royal court, where they rose to positions of influence and converted Emperor Ezana to Christianity, causing him to be baptised. Ezana sent Frumentius to Alexandria to ask the Patriarch, St. Athanasius, to appoint a bishop for Ethiopia. Athanasius appointed Frumentius himself, who returned to Ethiopia as Bishop with the name of Abune Selama.