GREGORY OF DECAPOLIS, Saint. - Monk, promoter of monastic life, thaumaturge, defender of the cult of the sacred images; b. at Irenopolis in Isauria around 780 and d. at Constantinople on 20 Nov. 842. In his many travels he also came to the West: Reggio, Naples, Rome, Syracuse, Otranto.
Initiated into monastic life after fleeing from his father's house, which had already found him a bride, in the mountains of his homeland he had no little suffering from the monks who favored iconoclasm, and he withdrew to his uncle Simeon, hegumen of another monastery of the Isaurian Decapolis, where he remained for 14 years.
G. also stayed in other Eastern monasteries, especially at Thessalonica and at Constantinople. One of his disciples was St. John the Monk; St. Joseph the Hymnographer also came under his moral influence. During the iconoclast struggle G. sent St. Joseph himself to Rome to the Pope to ask for his support against the heresy promoted by the emperors and the patriarchs. But the latter was captured during his journey toward Rome by the Saracens and only later was able to return to Constantinople, when G. was dead. In honor of the latter, of the aforementioned monk St. John and of St. Bartholomew, he built a monastery and a church where the mortal remains of G. and of his disciple John were transferred alongside the relics of St. Bartholomew.
A discourse on the conversion of a Muslim is attributed to G. (PG 100, 1200 A-1212 D), but the authenticity of this opuscule is disputed. A life of G. written by the deacon Ignatius, author of the lives of the holy patriarchs Nicephorus and Tarasius, also provides interesting contributions to certain Byzantine historical questions of the 9th century, especially concerning the Balkan Slavs and the spread of iconoclasm; a new critical edition of the Greek life of G. with an introduction was made by Dvornik, an expert in such matters; yet he overlooked the manuscript of Messina already pointed out in 1884 by D. G. Lancia di Brolo in his Storia della Chiesa in Sicilia (II, Palermo 1884, p. 295). This author also gives the precious notice that St. Joseph the Hymnographer composed a poem (canon) in honor of G., published in the Menaia (II, Rome 1889, pp. 203 ff.). A hontahion, likewise by St. Joseph in honor of G., was edited by E. Mioni, I hontahia inediti di s. Giuseppe innografo, in Bollettino della badia greca di Grottaferrata, new series, 2 (1948), pp. 181-82.