Who was Saint John Chrysostom?
Saint John Chrysostom was born in Antioch around the year 349, and after an extensive education embraced a life of asceticism. He was the Archbishop of Constantinople from approximately 397 to 407, during a period of great reform and renewal among the clergy and faithful of the Byzantine Roman Empire. Twice he was forced into exile by enemies and the imperial court, and died at Comana in Pontus, Asia Minor (present-day Turkey).
What did he do?
Because of his exceptional preaching and writings to explain Christian doctrine, he is called Chrysostom, or Golden Mouth. The Divine Liturgy attributed to him is the most celebrated among all the Byzantine Churches today. His sermons, especially a famous one given on the Feast of the Resurrection of Our Lord, are studied today for their theological and pastoral content. It is frequently read in its entirety on Pascha (Easter).