Eustathius, archbishop of Thessalonica, Byzantine scholar and author (probably a native of Constantinople), flourished during the second half of the 12th century. He was at first a monk, and afterwards deacon of St Sophia and teacher of rhetoric in his native city. In 1174 he was chosen bishop of Myra in Lycia, but in 1175 was transferred to Thessalonica. He was outspoken and independent, and did not hesitate to oppose the emperor Manuel, when the latter desired an alteration in the formula of abjuration necessary for converts from Mahommedanism. In 1185, when Thessalonica was captured by the Normans under William II. of Sicily, Eustathius secured religious toleration for the conquered. He died about 1193. His best known work is his Commentary on the Iliad and Odyssey of Homer (παρεκβολαί, critical compilations), valuable as containing numerous extracts from the scholia of other critics, whose works have now perished. He also wrote a commentary on the geographical epic of Dionysius Periegetes, in which much of Stephanus of Byzantium and the lost writings of Arrian is preserved. A commentary on Pindar has been lost, with the exception of the preface, which contains an essay on lyric poetry, a life of Pindar, and an account of the Olympic games. A history of the conquest of Thessalonica by the Normans, a congratulatory address to the emperor Manuel, a plea for an improved water-supply for Constantinople, and an extensive correspondence with clerical and lay dignitaries, are evidence of his versatility. He is also the author of various religious works, chiefly directed against the prevailing abuses of his time, which almost anticipate, though in a milder form, the denunciations of Luther; the most important of these is The Reform of Monastic Life. A commentary on the pentecostal hymn of John of Damascus may also be mentioned.
Editions: Homer Commentary, by G. Stallbaum (1825-1830); preface to Pindar Commentary, by F.W. Schneidewin (1837); Dionysius Commentary in C.W. Müller, Geographici Graeci minores, ii.; pentecostal hymn, in A. Mai. Spicilegium Romanum, v. 2 (1841). The smaller works have been edited (1832) and the De Thessalonica (1839) by L.F. Tafel; many will be found in J.P. Migne, Patrologia Graeca, cxxxv., cxxxvi. Five new speeches have been edited by W. Regel, Fontes rerum Byzantinarum, i. (1892).
