"Saint Irenaeus, (born c. 120, /140, Asia Minor—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, and the authority of the episcopal office." (Encyclopedia Britannica, s.v. "Saint Irenaeus," accessed February 27, 2018, https://www.britannica.com/biography/Saint-Irenaeus).