He inherited great wealth but resolved to devote his riches and his talents to the service of the church.
The Bishop of Rome and the Patriarch of Alexandria refused to acknowledge Flavian I, and Paulinus II of Antioch, who by the extreme Eustathians had been elected patriarch in opposition to Meletius, continued to exercise authority over a portion of the church.
After the death of Evagrius, (c. 392) Flavian succeeded in preventing the election of a successor, though the Eustathians still continued to hold separate meetings.
Through the intervention of John Chrysostom soon after his elevation to the patriarchate of Constantinople in 398, and the influence of the emperor Theodosius I, Flavian I was acknowledged in 399 as the sole legitimate patriarch of Antioch.
[3] Flavian is posthumously venerated in both the Western and Eastern churches as a Saint.