I mentioned previously the Ethiopian Orthodox saint listed in the Roman Martyrology, King St. Kaleb Elasbaan. He's currently one of the saints for May 15 (in the 2004 Roman Martyrology) and here is the entry for him :
In Aethiopia, sancti Caleb seu Elasbaan regis, qui ad ultionem martyrum Negranensium, Christi hostibus expugnatis ac, tempore Iustini imperatoris, regio, ut fertur, misso Hierosolymam diademate, monasticam vitam, sicut voverat, agens, ad Dominum migravit.
I suppose this would be something like, very roughly: "In Ethiopia, King Saint Caleb or Elasbaan, who in vindication of African martyrs conquered the enemies of Christ and, in the time of the Emperor Justin, so it is said, acting as he had vowed to the Lord, having sent his crown to Jerusalem, transferred to monastic life."
As with all comments in the Martyrology, it is brief to the point of obscure, but the essential elements that seem to have led to St. Kaleb being entered into the Roman Martyrology seem to have been:
(1) King Kaleb happened to be an ally at the time of the Emperor Justin I; across the Red Sea from Ethiopia in Yemen (also known as Eudaimon Arabia), more or less, the rising king Dhu Nuwas (Dunaan to the Greeks) of the kingdom of Himyar began a massive campaign to eliminate Christianity from the area; these Christians had fairly close trading ties with both the Byzantines and the Ethiopians. According to one story, Justin I asked St. Kaleb to do something about it, so the Ethiopian king crossed the Red Sea with an army and reconquered the area. (In other stories, fleeing Christian refugees were the ones who made the request.)
(2) Later in life, he gave up his royal status, sending his crown to the Church of the Holy Sepulcher in Jerusalem, and lived out the rest of his life as a monk.
