(Εἰρηναῖος). A native of Greece, disciple of Polycarp, and bishop of Lyons, in France. The time of his birth and the precise place of his nativity cannot be satisfactorily ascertained. On the martyrdom of Photinus, his predecessor in the see of Lyons, Irenaeus, who had been a distinguished member of the church in that quarter, was appointed his successor in the diocese, A.D. 177, and presided in that capacity at two councils held at Lyons, in one of which the Gnostic heresy was condemned and in another the Quartodecimani. He also went to Rome, and disputed there publicly with Valentinus, Florinus, and Blastus, against whose opinions he afterwards wrote with much zeal and ability. He wrote on different subjects; but there remains only a barbarous Latin version of a work, Adversus Haereses, in five books, written to confute the Gnostics and Ebionites. Fragments of his works in Greek are, however, preserved, which prove that his style was simple, though clear and often animated. His opinions concerning the soul are curious. He is said to have suffered martyrdom about A.D. 202. His day is the 28th of June. The editio princeps of the Adversus Haereses is that of Erasmus (Basle, 1526). The best editions are those of Stieren (Leipzig, 1851-53) and Harvey (Cambridge, 1857). There is an English translation in Clark's Ante-Nicene Library. On the views of Irenaeus, see Werner, Der Paulinismus des Irenaeus (1890).