FLAVIAN, SAINT (d. 449) , bishop cf Constantinople and an adherent of the Antiochene school, succeeded Proclus in 447. He presided at the council which deposed Eutyches (q.v.) in 448, but in the following year he was deposed by the council of Ephesus (the "robber synod"), which reinstated Eutyches. Flavian's death was attributed to ill treatment at the hands of his theological opponents. The council of Chalcedon (451) canonized him as a martyr, and in the Latin Church he is commemorated on Feb. 18.
Three of Flavian's letters are preserved in Migne, Patr. Lat. S4 and Patr. Graec. 65. His appeal to Pope Leo I. against the council of Ephesus was edited by Lacey (Cambridge, 1903).