AGATANGELO. - Armenian historian of the fourth century, Roman by nationality. At the behest of King Tiridate he wrote the history of the latter, of St. Gregorio Illuminatore, and of the conversion of Armenia to Christianity.
However, the critical studies of A. von Gutschmid, Sarghissian, Tašian, etc. show that the work attributed to A. is composed of various writings: History of Tiridate and of St. Gregorio Illuminatore; History of the Martyrdom of the Virgins Hriphsimiankhi; Doctrine of St. Gregorio Illuminatore; Vision of St. Gregorio Illuminatore, compiled in the fifth century by an Armenian and in the Armenian language, whereas the History of Tiridate in its primitive form may have been composed by A. himself in Greek or Latin. The Acts of St. Gregorio Illuminatore have also come down to us in Greek and Arabic; the Greek is a translation of the Armenian text and was published with the Latin version by P. G. Stilting in the Acta SS. Septembris, VIII, Bruxelles 1867, pp. 320 ff. The Mechitarists of Venice prepared an Italian version of A., with notes and revised, as regards style, by N. Tommaseo (Venice 1843).