SIXTUS III, Pope, Saint. - He reigned from 432 to 440. It is not established that he was venerated in antiquity; he was included by Ado in his Martyrology, from which he passed into the Roman one, where he is commemorated on 28 March.
A Roman, son of the priest Sixtus, it appears that, being himself also a priest, he had sympathies for the Pelagians; but after the condemnation of the heresy by Pope Zosimus (418) he abandoned them definitively and even wrote some vigorous letters against them, so much so that St. Augustine had to call him back to greater prudence and charity. He succeeded Celestine (432) when the Nestorian heresy had already been condemned (Ephesus, 431; already in 430 he himself had written directly to Nestorius exhorting him to abandon his error), but he found the Churches of the East divided over the well-known question between St. Cyril and John of Antioch. He had, however, the consolation of learning of the reconciliation that had taken place in 433 and wrote congratulating the two protagonists. Recalling his former sympathy for the Pelagians, Julian of Eclanum sought to intrigue so that he might be readmitted to ecclesiastical communion, but S., advised by Leo, the future pope, did not allow himself to be deceived.
A faithful continuer of the primatial activity of his predecessors, he wrote a letter to Proclus of Constantinople warning him not to interfere in the affairs of Illyricum, while he confirmed Anastasius of Thessalonica as his vicar for those regions with the right to confirm the appointments of bishops, judge questions, and convoke and preside over synods. No less important was the building activity of S. In memory of the dogmatic definition of Ephesus, which sanctioned the divine motherhood of Mary, he rebuilt and enlarged the Liberian Basilica, adorning it with the splendid mosaics still in existence; he arranged the Lateran Baptistery as it is still seen today; he adorned the confessios of the basilicas of St. Peter and St. Paul and built a monastery "in catacumbas".
He died in August 440 and was buried outside the walls near the tomb of St. Lawrence. One of the "Symmachian apocrypha" (v. SIMMACO), Cesta de Xisti purgatione, concerns S. In 433 the former consul Bassus accused the Pontiff of unchastity. Valentinian III then convoked a synod in S. Croce, at which S. succeeded in proving his innocence; Bassus was excommunicated. When the latter then died, three months later, the Pope himself wished to preside at the funeral and buried him in St. Peter's.
Bibliography5 works
Agostino Amore