FLACILLO, intruded bishop of ANTIOCHIA. - D. shortly before the Council of Sardica. He was always favorable to the Arians. In 335 he presided over the Council of Tyre, which deposed St. Athanasius. In 339 he supported the election at Alexandria of the intruder Gregory the Cappadocian.
He was among the signatories of the letter of protest to Pope Julius I because the latter had recognized the innocence of Athanasius and had intervened in Eastern affairs. In 341 he convened the so-called Council of the Dedication, attended by about 100 bishops; the Council renewed the condemnation of Athanasius and composed a formula of faith open to orthodox interpretation, but without the term ἀμπούσιος.
BIBL.: S. Atanasio, Apologia contra Arianos, 3-35; Socrate, Hist. eccl., II, 9; Sozomeno, Hist. eccl., III, 6-6; Tillemont, VI, Venezia 1732, pp. 284-86; C. Karolevskii, Autoche, in DHG, III, col. 572; R. Devreese, Le patriarchat d'Autoche, Patig. 1945, pp. 3, 116. Vincenzo Monachino