died c. 200, /203, probably Lyon; Western feast day June 28; Eastern feast day August 23
bishop of Lugdunum (Lyon) and leading Christian theologian of the 2nd century. His work Adversus haereses (Against Heresies), written in about 180, was a refutation of Gnosticism. In the course of his writings Irenaeus advanced the development of an authoritative canon of Scriptures, the creed,