Saint Artemia was the daughter of the Emperor Diocletian, and suffered from demonic oppression. Learning that the prisoner Saint Cyriacus could heal infirmities and cast out devils, the emperor summoned him to the sick girl. In gratitude for healing his daughter, the emperor freed Cyriacus, Smaragdus and Largus. Soon the emperor sent Saint Cyriacus to Persia to heal the daughter of the Persian emperor.
Upon his return to Rome, Saint Cyriacus was arrested on orders of the emperor Galerius, the son-in-law of Diocletian, who had abdicated and retired as emperor. Galerius was very annoyed at his predecessor because his daughter Artemia had converted to Christianity. He gave orders to drag Saint Cyriacus behind his chariot stripped, bloodied, and in chains, to be shamed and ridiculed by the crowds.
Saint Marcellus denounced the emperor openly before everyone for his cruelty toward innocent Christians. The emperor ordered the holy bishop to be beaten with rods, and dealt severely with him. Saints Cyriacus, Smaragdus, Largus, and another prisoner, Crescentian, died under torture. And at this time the emperor’s daughter Artemia and another twenty-one prisoners were also executed with Saint Cyriacus.