fl. c. 1214 to 1294
'Iyäsus-Mo'a, Abba, saint of the Ethiopian Church, was the founder and abbot of the monastery of St. Stephen in an island in Lake Hayq in Wällo. His name means "Jesus has won." One of the most eminent personalities of Ethiopian monasticism, he was born, according to the Gädlä 'Iyäsus-Mo'a composed in the fifteenth century, in Dahna, in Bägémder, to Zä-Krestos and 'Egzi'e-Kebra. In his thirtieth year he went to the monastery of Däbrä Damo, where, after seven years of novitiate, he received the monastic habit and scapular from Abba Yohanni. He was then appointed abbot of the monastery of Däbrä Hayq by one of the kings of the Zagwé dynasty. He remained there for forty-four years, until his death. He is said to have been the spiritual father of St. Täklä-Haymanot, who stayed with him on the island for ten years.
Traditionally, 'Iyäsus-Mo'a played a leading part in the restoration of the Solomonic dynasty in or about 1270: thanks to his help Emperor Yekuno-'Amlak obtained the throne, in gratitude for which he endowed the monastery with privileges, including the gift to 'Iyäsus-Mo'a's disciple, Abba Zä-'Iyäsus, of the office of 'agabé sä'at and one-third of the property of the realm. In the fifteenth century, however, Däbrä Hayq lost its privileges; another tradition appeared, applying the historical role of 'Iyäsus-Mo'a and the powers received by him to Täklä-Haymanot and the monastery of Däbrä Libanos of Šäwa, whose abbot stood at the head of the regular clergy.
In the list of the spiritual sons of 'Iyäsus-Mo'a, figure the great names of Ethiopian monasticism: St. Täklä-Haymanot, Abba Bä-Sälotä-Mika'él, 'Aron (Ecca-Aron of Däbrä Darét or Aron the Thaumaturge), and Abba Giyorgis of Gasecca. The Ethiopian Church commemorates 'Iyäsus-Mo'a on 26 Hedar (5 December). The most famous of his mortifications was that for fifty years of his monastic life he did not sleep on his side, but in a sitting position, according to the rule of Pachomius.
S. Kur (ed. and trans.), Actes de Iyasus Mo'a,Corpus Scriptorum Christianorum Orientalium, Scriptores aethiopici, t. 49 and t. 50.
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--------, The Book of the Saints of the Ethiopian Church (Cambridge, 1928), Vol. I, 293; Vol. IV, 1244-5.
B. Turaiev, Acta Sancti aaronis,, Corpus Scriptorum Christianorum Orientalium, series altera, t. XX, 141, 158.
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Enrico Cerulli, Storia della letteratura etiopica (Milano, 1961), 94-7.
--------, "Gli abbati di Dabra Libanos, capi del monachismo etiopico, secondo la lista rimata", Orientalia, N. S. Vol. XII (1943): 229 ff.; Vol. XIII (1944): 145.
A. Pollera, Lo stato etiopico e la sua chiesa (Roma - Milano, 1926), 34-7, 177-81, 227, 231-3.
V. V. Bolotov in Khristianskoye Chtenye (Feb. 1898), 289-98.
Taddesse Tamrat, "The Abbots of Däbrä-Hayq 1248-1535," Journal of Ethiopian Studies, Vol. VIII, No. 1 (1970).
--------, Church and State in Ethiopia 1270-1527 (Oxford, 1972), 67, 110, 112, 114, 158-67, 174, 177-8, 197, 203, 232.