Frumentius' story, as related by Rufinus of Aquilea, a near contemporary of the events, is an extraordinary one. He and a relative, Aedesius, were taken as children by a kinsman, a philosopher called Meropius, (p41) to India. On returning from India, their ship touched at an Ethiopian port, but, a Romano-Ethiopian treaty having been at that moment broken, all on the ship were slain except for the two youths.
The philosopher's ship was boarded; all with himself were put to the sword. The boys were found studying under a tree and preparing their lessons, and, preserved by the mercy of the barbarians, were taken to the king. He made one of them, Aedesius, his cupbearer. Frumentius, whom he had perceived to be sagacious and prudent, he made his treasurer and secretary.
Later, on the king's death, the queen, regent for a minor son, asked Frumentius to assist her in ruling the ' land. Despite their having been granted their freedom, he and Aedesius stayed. Frumentius took the opportunity to propagate the Christian faith, with the result that, when he finally left the country to return to the Roman world, there was already a nascent Church.
Frumentius went to Alexandria, saying that it was not right to hide the work of God. He laid the whole affair before the bishop [Athanasius, patriarch of Alexandria) and urged him to look for some worthy man to send as bishop over the many Christians already congregated and the churches built on barbarian soil. Then Athanasius ...declared in a council of the priests 'What other man shall we find in whom the spirit of God is as in thee, Who can accomplish these things?' And he consecrated him, and bade him return in the grace of God whence he had come.
Athanasius' consecration of Frumentius to this post (around AD 340) officially founded the Ethiopian Church. This story is told by a contemporary historian, Rufinus of Aquilea, who claims to have heard it in person from Aedesius, who later became a priest in Tyre.
Christianity evidently took root, in court circles at least, in King Ezana's time. The king's coins and inscriptions employed pagan symbolism or phraseology at first, changing later to Christian. It is thus fairly certain that the unnamed kings of Rufinus' account were Ezana and his father Ella Amida, who seems to be identifiable as the king called Ousanas on his coins – the usual problem posed by Ethiopian rulers' use of several names. In addition, a letter written about AD 356 by the Roman emperor Constantius II about Frumentius himself is addressed to the brothers 'Aizanas and Sazanas', and Ezana is known from some of his pagan inscriptions to have had a brother called Sazana. However, later Ethiopian records do not preserve the names Ezana or Sazana known from the earlier inscriptions; only the twill names 'Abreha and Asbeha' are found in Ge'ez accounts of the conversion of the country.
How quickly the new faith spread from this 'conversion from above' among (p 42) the people themselves is unknown, but Ethiopian records tell us that in the fifth and sixth centuries numerous foreign missionaries, particularly the famous 'Nine Saints', came and established themselves in the Aksumite countryside. Their names are to be heard still in church dedications and local tales: Za-Mikael Aregawi, Liqanos or Mata'a, Pantalewon, Guba, Afse, Garima, Yemata, Alef and Sehma. These monks or hermits, even if the records pertaining to them date from nearly a thousand years later, and are not to be taken at face value, seem to continue a memory of a secondary Christian impetus that spread the faith into regions more distant from the capital, and doubtless also reached to a different level of society.
(from S. M-H, “Ethiopia, The Unknown Land” p. 40-42)