Born of a Florentine noble family, Zenobius was educated by his pagan parents. He came under the influence early of the bishop Theodore, was baptized by him, and succeeded, after much opposition, in bringing his father and mother to Christianity. He embraced the clerical state, and rapidly rose to the position of archdeacon, when his virtues and notable powers as a preacher made him known to Saint Ambrose, at whose instance Pope Damasus I (r. 366–386) called him to Rome, and employed him in various important missions, including a legation to Constantinople. On the death of Damasus he returned to his native city, where he resumed his apostolic labours, and on the death of the bishop of that see, Zenobius, to the great joy of the people, was appointed to succeed him. His deacons are venerated as Saint Eugene and Saint Crescentius.Cathedral and Civic Ritual in Late Medieval and Renaissance Florence – Cambridge University Press He evangelized Florence and its outskirts completely and combated Arianism.
