ARSENIUS (c. 354-450), an anchorite, said to have been born of a noble Roman family, who achieved a high reputation for his knowledge of Greek and Roman literature. He was appointed by Theodosius the Great, tutor of the young princes Arcadius and Honorius, but at the age of forty he retired to Egypt, where for forty years he lived in monastic seclusion at Scetis in the Thebais, under the spiritual guidance of St John the Dwarf. He is said to have gained the admiration of his fellows by the extreme rigour of his asceticism. The remainder of his life he spent at Canopus, and Troe near Memphis, where he died at the age of ninety-five. Of his writings two collections of admonitory maxims are extant: the first, [Greek: Didaskalia kai parainesis], containing instructions for monks, is published with a Latin version by Fr. Combefis in _Auctarium biblioth. patr. novissim._ (Paris, 1672), pp. 301 f.; the second is a collection of forty-four wise sayings put together by his friends under the title of [Greek: Apophthegmata] (see Cotelerius, _Eccl. graec. monum._, 1677, i. pp. 353-372). In the Roman Catholic Church his festival is on the 19th of July, in the Orthodox Eastern Church on the 8th of May. His biography by Simeon Metaphrastes is largely fiction. ARSENIUS AUTORIANUS (13th century), patriarch of Constantinople, lived about the middle of the 13th century. He received his education in Nicaea at a monastery of which he later became the abbot, though not in orders. Subsequently he gave himself up to a life of solitary asceticism in a Bithynian monastery, and is said, probably wrongly, to have remained some time in a monastery on Mount Athos. From this seclusion he was in A.D. 1255 called by Theodore II. Lascaris to the position of patriarch at Nicaea, and four years later, on that emperor's death, became joint guardian of his son John. His fellow-guardian Georgios Mouzalon was immediately murdered by Michael Palaeologus, who assumed the position of tutor. Arsenius then took refuge in the monastery of Paschasius, retaining his office of patriarch but refusing to discharge its duties. Nicephorus of Ephesus was appointed in his stead. In 1261 Michael, having recovered Constantinople, induced Arsenius again to undertake the office of patriarch, but soon incurred his severe censure by ordering the young prince John to be blinded. Arsenius went so far as to excommunicate the emperor, who, having vainly sought for pardon, took refuge in false accusations against Arsenius and caused him to be banished to Proconnesus, where some years afterwards (according to Fabricius in 1264; others say in 1273) he died. Throughout these years he declined to remove the sentence of excommunication which he had passed upon Michael, and after his death, when the new patriarch Josephus gave absolution to the emperor, the quarrel was carried on between the "Arsenites" and the "Josephists." The "Arsenian schism"