AMBROGIO, DIACONO. - Disciple and correspondent of Origene, confessor of the faith. Of a noble and wealthy family, perhaps Alexandrian, he was a deacon, although he had a wife and children. Having been led to embrace a Gnostic sect, he was converted around 212 by Origene. From then on he remained faithful to his master and not only encouraged him in every way to compose various works, but also provided him with the means to write them and to pursue his studies more deeply. During the persecution of Massimino, A. was imprisoned and ill-treated, but was finally released. He died not long afterwards, shortly before Origene himself.
Among the numerous works dedicated to him by Origene, special note should be made of the Echortatio ad martyrium, which he sent him while he was in prison (PG 11, 563-638), and of the Contra Celsum, composed at the urging of A. himself.