Tiburtius, the only son of Chromatius, was also baptized through the persuasion of Sebastian, who was his godfather in baptism.
Tiburtius lay hidden during the persecution by Roman Emperor Diocletian in his father's house. Accused by a traitor, he was brought before the prefect Fabianus and tried. He confessed his faith which he confirmed by a miracle, for protecting himself only by the sign of the cross he walked over red-hot coals barefoot without suffering any injury. But the miracle was ascribed to magic and Tiburtius was beheaded at the third mile-stone of the Via Labicana in the year 286. The spot of execution was called "at the two laurel trees" (ad duas lauros).
Tiburtius is mentioned in the Roman Martyrology for 11 August in the following terms: "At Rome, in the cemetery at the two laurel trees at the third milestone on the Via Labicana, Saint Tiburtius, martyr, whose praises Pope Saint Damasus sang."
Susanna is mentioned in the Roman Martyrology for 11 August in the following terms: "At Rome, commemoration of Saint Susanna, in whose name, which was mentioned among the martyrs in ancient lists, the basilica of the titular church of Gaius at the Baths of Diocletian was dedicated to God in the sixth century." The commemoration of her that was included in the Roman Catholic calendar of saints required to be observed wherever the Roman Rite is celebrated was removed in 1969!