After having aided for some time his uncle, the aged Bishop of Marseilles, in the administration of his diocese, Father De Mazenod was called to Rome and, on 14 October 1832, consecrated titular Bishop of Icosium, which title in 1837 he exchanged for that of Bishop of Marseilles, a position he held until his death in 1861. During his episcopacy, he commissioned Notre-Dame de la Garde, an ornate Neo-Byzantine basilica on the south side of the old port of Marseille. He favoured the moral teachings of Alphonsus Liguori, whose theological system he was the first to introduce in France, and whose first biography in French he caused to be written by one of the Oblates.