Saint Dionysius, the first pope not to die a martyr's death, is included among the saints in the current Roman Martyrology; his feast is presently commemorated on December 26th.
WE beseech Thee, O Lord! to heal our vices by the remedies of Thy mercy, that, through the holy intercession of Blessed Dionysius, Thy Confessor and Pontiff, we may rise to heavenly desires. Through our Lord Jesus Christ, Your Son Who lives and reigns with You in the unity of the Holy Spirit one God, forever and ever. Amen.
Dionysius followed the example of those holy leaders of the religious life who built for themselves little huts near the waters of the Jordan, and, leaving crowded cities behind, made wild herbs their food. In like manner Dionysius lived for a time after the manner of the monks or anchorites, and led in very truth the life of a prophet. He was raised thence to the Chair of the Supreme Pontiff, and governed the Church under the Emperors Valerian and Gallienus. He called a council together in Rome, to judge the cause of Dionysius of Alexandria, who had been sent to him by certain bishops of Pentapolis, under the charge of unsound faith. The Pope commanded Dionysius of Alexandria to give an account of his belief, and, having judged him innocent, absolved him.
He overthrew, by written commentaries on doctrine, the heresy of Sabellius, which was then springing up; and his commentaries were like a middle and royal road, inasmuch as they refuted the two opposite heresies of Sabellius and Anus. He condemned the heresiarch Paul of Samosata, in two councils which were called together at Antioch; and when peace was restored for a time, under Gallienus, the watchful Pontiff placed priests over the different catacombs and churches which had been deprived of their pastors during the cruel persecution of Valerian.
He established, besides, parishes and dioceses without the city, and gave his approval to many other things which were of the greatest advantage to the Church. At length, after he had borne many labors in defending the Church against heretics and persecutors, and after having reigned eleven years three months and fourteen days, he passed hence, in peace, to the Lord, and was buried in the catacombs of Callistus, in the Appian Way. He held two ordinations in the month of December, in which he made twelve priests, six deacons, and seven bishops for different places.
Taken from the book “Saints of Carmel” (BOSTON: JOHN CASHMAN & CO., 1896).