The story of St. Donatian and his brother St. Rogatian is known from a 5th century document, "the Passion of Children of Nantes". St. Donatian and St. Rogatian were, it seems, the sons of the first magistrate of the city. Donatian, the youngest, was baptized (probably by St. Similien, third bishop of Nantes, who outlived them). Donatian then evangelized his older brother, Rogatian....