(Εἰρηναῖος).
1. St., bishop of Lyon, in Gaul, during the latter part of the second century after Christ, seems to have been a native of Smyrna, or of some neighboring place in Asia Minor. The time of his birth is not known exactly, but Dodwell is certainly wrong in placing it so early as A. D. 97; it was probably between A. D. 120 and A. D. 140. In his early youth he heard Polycarp, for whom he felt throughout life the greatest reverence. The occasion of his going from Asia to Gaul is uncertain; the common account is that he accompanied Pothinus on his mission to Gaul, which resulted in the formation of the churches at Lyon and Vienne. He became a presbyter to Pothinus, on whose martyrdom, in A. D. 177, Irenaeus succeeded to the bishopric of the church at Lyon. His government was signalised by Christian devotedness and zeal, and he made many converts from heathenism. He was most active in opposing the Gnostics, and especially the Valentinians. He also took part in the controversy respecting the time of keeping Easter, and wrote a letter to Victor, bishop of Rome, rebuking the arrogance with which he anathematised the Asiatic churches. Irenaeus seems to have lived till about the end of the second century. The silence of all the early writers, such as Tertullian, Eusebius, Augustin, and Theodoret, sufficiently refutes the claim to the honours of martyrdom, which later writers set up in his behalf. But he eminently deserves the far higher honour attached to sincere piety and the zealous, but not arrogant discharge of his episcopal duties. He was possessed of considerable learning, but was very deficient in sound judgment respecting the value of those traditions, which, as they came from men who lived in the age next to the apostles, he eagerly received and recorded. On the subject of the Millennium, for example, his writings contain the most puerile absurdities.