Election of Saint Celestine I as 43rd successor of Peter. He called the Third Ecumenical Council which condemned the followers of Nestorius, the Patriarch of Constantinople. Celestine sent Saint Patrick to Ireland and mention is first made during this period of the "pastoral staff."
Death of Saint Pulcheria, daughter of the Byzantine emperor who was instrumental in convincing authorities to condemn the heresies of Nestorius and Eutychius and recall orthodox bishops who had been exiled. She stood staunchly behind the orthodox reforms called for by Pope Saint Leo the Great and he credited her with helping save Catholicism in Constantinople where she died on this date.
Death of Saint Nicholas of Tolentino of the Hermits of Saint Augustine. So devoted was this holy priest to saving souls that God mystically would reveal the souls admitted into Heaven as a result of his prayers and devout Masses.
Death of 205 Japanese and European martyrs, including Blessed Sebastian Kimura and Blessed Lucy de Freitas who were burned to death by Shogun warriors along with the other Catholics. Blessed Lucy, a widow of a Portuguese trader, sought to hide European priests during this time of persecution including Fr. Kimura who secretly ministered to Japanese Catholics who were being forced by the Japanese regime to abandon their faith.