Feast Day : March 28
Also known as: Xystus III
Not much is known about Sixtus III. He was prominent in the Roman Church when he was elevated to the Chair of St. Peter, succeeding St. Celestine I (r. 422–432) on July 31, 432. Sixtus III was falsely accused of sympathy toward Nestorianism and Pelagianism, against both of which heresies he acted. He also defended the pope’s right of supremacy over the ecclesiastical province of Illyricum against Proclus of Constantinople. In Rome, he restored the basilica of Liberius (now St. Mary Major) and enlarged the basilica of St. Lawrence-Outside-the-Walls. He received precious gifts from Emperor Valentinian III for St. Peter’s and the Lateran basilica.