Ethiopian Literature 

I have no information about this.  I believe that Rufinus gives the story of how Christianity came to Ethiopia.  Ships from Egypt had traded down the Red Sea since Pharaonic times.  In the 4th century, two Greeks on a ship came to the kingdom of Axum, modern Eritraea, and started to evangelise the country.  They met with so much success, that one returned to Alexandria and asked the patriarch to consecrate a bishop.  The patriarch decided that the man before him was the most appropriate, already knowing the people, and ordained him.  The Ethiopian patriarch, even today, is appointed by the Coptic pope.  As an outsider, he has no political influence and so remains a purely religious figure.

Various works have been preserved in only in Ethiopic, no doubt through the link with Egypt.  These include the Chronicle of John of Nikiu (online elsewhere on this site), and 1 Enoch.

J. M. HARDEN, An Introduction to Ethiopic Christian Literature. London, 1926.  Not checked.   (Details from Quasten)
J. GUIDI, Storia della letteratura etiopica. Rome, 1932.  Not checked  (Details from Quasten)
Alessandro BAUSI, L'Epistola 70 di Cipriano di Cartagine in versione etiopica. Aethiopica, International Journal of Ethiopian Studies 1 (1998), pp. 101-130.  (Details from CTC 99, 9).  Translated from a Greek translation, but of a different family to that preserved by 2 12th century Byzantine compilers, John Zonaras & Theodore Balsamon.  Based on 5 MSS from s.XIV-XIX.  Not checked

Constructive feedback is welcomed to Roger Pearse.