ARSENIO AUTOREIANO. - Born in Constantinople at the beginning of the thirteenth century, he changed his name from Giorgio to A. when he entered the monastery of Oxia, near Nicea, where he became hegumen. He complied with all the wishes of Emperor Teodoro II Lascaris, who had chosen him patriarch of Constantinople (1254). When, in 1258, Michele Paleologo seized power, A. threatened him, abandoned the patriarchal see, and agreed to return only on condition, after the death of his successor, Niceforo di Efeso. He crowned Michele in S. Sofia; but when Paleologo, in 1261, had Giovanni Lascaris, son of the late emperor and ward of the patriarch, blinded, A. excommunicated him. The emperor had him deposed, and he went to die on the island of Proconnesso, in 1237, leaving a serious schism behind him.
Works: 1) Testament: a historical document of the period, PG 140, 947-58. 2) Bulls. 3) Part of the ritual of the Union: ibid., 808. 4) An unpublished treatise contained in ms. 7 Lincoln at Oxford. He is wrongly credited with a Synopsis Canonum written in 1255 by another A., a monk of Mount Athos.