Isaija's commentaries on political events occur in the context of the fall of the Serbian principality of Serres in 1371, which led the descendants of these local governors to accept Ottoman suzerainty.
[1] As a young boy, Isaija joined the monastic life of the Serbian Orthodox Church affiliated to St. Joachim of Osogovo Monastery on Osogovo Mountain in northern Macedonia, and then to Hilandar Monastery on Mount Athos in Greece, where he spent the rest of his life.
In Hilandar, he worked as a translator and became very respected by Serbian rulers as attested to by the anonymous author of The Life of the Monk Isaija, probably written in the late 14th century.
The climate of despair which set in after the Battle of Maritsa in 1371 is expressed in a long personal comment, written by Isaija the Monk.
This literary comment is appended to Isaija's translation of the works of Pseudo-Dionysius the Areopagite into Old Serbian which, he says, he had started " in happy times," but had finished it after the battle, "when Ishmelites spread over the entire land as birds in the air, slaying some of the Christians, sending others into slavery... And the land became deprived of all that is good, people, beast, the fruit of all kind.