The account of his martyrdom
Saint Sixtus II, Pope, Martyr (d. 258)
Saint Sixtus was ordained bishop of the Church of Rome in 257. The following year, while celebrating the sacred liturgy in the cemetery of Saint Callistus, he was arrested by soldiers carrying out the first edict of persecution of Christians issued by the Emperor Valerian. This edict made it binding upon Christians to participate in the national cult of the pagan gods and forbade them to assemble in the cemeteries, threatening with exile or death whomsoever was found to disobey the order.
For a time, Sixtus II managed to perform his functions as chief pastor of the Christians without being molested by those who were charged with the execution of the imperial edict.
But during the first days of August, 258, the emperor issued a new and far more cruel edict against the Christians. It ordered bishops, priests, and deacons to be summarily put to death. Sixtus II was one of the first to fall a victim to this imperial order.
In order to escape the vigilance of the imperial officers he assembled his flock on August 6 at one of the less-known cemeteries on the left side of the Appian Way, nearly opposite the cemetery of St. Callistus.
While seated on his chair in the act of addressing his flock he was suddenly apprehended by a band of soldiers. Four deacons, Januarius, Vincentius, Magnus, and Stephanus, were apprehended with Sixtus and beheaded with him at the same cemetery.
Two other deacons, Felicissimus and Agapitus, suffered martyrdom on the same day. The feast of St. Sixtus II and these six deacons is celebrated on August 6, the day of their martyrdom.
The remains of Sixtus were transferred by the Christians to the papal crypt in the neighboring cemetery of St. Callistus. Behind his tomb was enshrined the bloodstained chair on which he had been beheaded. An oratory (Oratorium Xysti) was erected above the site.