FLAVIANO, saint, patriarch of COSTANTINOPOLI. - An upright and moderate man, he found himself holding the episcopate in troubled times (446–49), precisely at the rise of Monophysitism. A Synod (Συνόδος ἐχθρώπων) held under his presidency in November 448 declared Eutyches a heretic and deposed him; F. sent a report of this to Pope St. Leo I.
The latter approved the Synod’s action and replied with the celebrated Epistola ad Flavianum (13 June 449). Teodosio II, influenced by the eunuch Crisafio, disapproved of the deposition of Eutyches and convened a new general Council at Efeso, assigning its presidency to F.’s personal adversary, Dioscoro of Alessandria. At the first session of the «Latrocinium Ephesinum» (8 August 449), Eutyches was declared orthodox, whereas F. was deposed and so severely maltreated that he died three days later, after having been able to send St. Leo I a fervent and urgent appeal. He was rehabilitated by the Fathers of the Council of Calcedonia and numbered among the saints as a martyr.