Hierarch Zosimus, Pope of Rome

St. Zosimus, of Greek origin, occupied the papal see in Rome from 417 to 418 — a brief but eventful pontificate. He became actively involved in the struggle against the Pelagian heresy, which denied the necessity of grace for salvation: he initially showed leniency toward Pelagius and Celestius, accepting their statements of faith, but under pressure from African bishops, including Blessed Augustine of Hippo, he reversed his position and in 418 finally condemned Pelagian teaching in a special letter (the "Epistola Tractoria") circulated throughout the Church. He attempted to expand the jurisdictional authority of the Bishop of Arles over other Gallic dioceses, provoking prolonged disputes with local metropolitans that remained unresolved during his lifetime. He died in December 418.