Cyprian and Justina, Christians of Antioch were martyred at Nicomedia, September 26, 304 during the persecution of Decius. Already in the same century, quite a colorful legend arose about them. The legend says that at the beginning of St. Cyprian's life he was anything but saintly. Much of his early training had taken place in North African Carthage, in modern Tunisia. He had been one of the leading sorcerers of the ancient world; he was a model and guide for many in the arts of darkness, and had ensnared many souls for evil. One time, as he was attempting by demonic means to seduce a young Christian virgin, Justina, on behalf of a lustful youth, Aglaidas, which backfired. St. Justina in her simplicity traced on herself the symbol of the Cross, at which the evil spirit fled. Cyprian's pride was stung. After many other unsuccessful attempts, Cyprian recognized the power of Christ and His Gospel. He not only renounced his old ways and was baptized, but soon thereafter became a deacon, then a priest, and finally a bishop.

http://www.catholicculture.org/culture/liturgicalyear/calendar/day.cfm?date=2013-09-26