 In 444–448, he rebuilt the church in Narbonne dedicated to Saint Genès of Arles, which had burned in 441; in 451, he assisted at the convocation of forty-four bishops of Gaul and approved St. Leo's letter to Flavian, concerning Nestorianism; he was present also at a Council of Arles, with thirteen bishops, to decide the debate between Theodore, Bishop of Fréjus, and the Abbey of Lérins.He was one of the twelve bishops who assembled to elect Ravennius bishop of Arles in 449; a letter from Ravennius to Rusticus, proves the high esteem in which he was held.Rusticus' own letters are lost, with the exception of the one to St. Jerome and two others to St. Leo, written either in 452 or 458.