Oecumenius (oikoumenios), Bishop of Trikka (now Trikkala) in Thessaly about 990 (according to Cave, op. cit. infra, p. 112). He is the reputed author of commentaries on books of the New Testament. A manuscript of the tenth or eleventh century containing a commentary on the Apocalypse attributes it to him. The work consists of a prologue and then a slightly modified version—of the commentary of Andrew of Caesarea (sixth cent.). Manuscripts of the eleventh century contain commentaries on the Acts and on the Catholic and Pauline epistles, attributed since the sixteenth century to Oecumenius. Those on the Acts and Catholic Epistles are identical with the commentaries of Theophylactus of Achrida (eleventh cent.); the Pauline commentaries are a different work, though they too contain many parallel passages to Theophylactus. The first manuscripts, however, are older than Theophylactus, so that it cannot be merely a false attribution of his work. It would seem then that Oecumenius copied Andrew of Caesarea and was himself copied by Theophylactus. The situation is however, further complicated by the fact that among the authors quoted in these works the name of Oecumenius himself occurs repeatedly. The question then of Oecumenius’s authorship is in all cases very difficult. Bardenhewer (Kirchenlex., IX, 1905, coll. 706-10) is doubtful about it; Ehrhard (in Krumbacher’s “Byzant. Litt.”, 132) says: “The name Oecumenius represents in the present state of investigation a riddle that can be solved only by thorough critical study of the manuscripts in connection with the whole question of the Catenae.” The commentary on St. Paul’s Epistles is a compromise between the usual kind of commentary and a catena. Most explanations are given without reference and are therefore presumably those of the author; but there are also long excerpts from earlier writers, Clement of Alexandria, Eusebius, Chrysostom, Cyril of Alexandria etc., especially from Photius. It is among these that Oecumenius himself is quoted. The Commentary on the Apocalypse was first edited by Cramer: “Catenae in November Test.”, VIII (Oxford, 1840), 497-582; the other three (on Acts, Cath. Ep., and St. Paul) by Donatus (Verona, 1532). Morellus (Paris, 1631) reedited these with a Latin translation; his edition is reproduced in P.G., CXVIII-CIX.