St. Irenaeus was a student of St. Polycarp in his youth. He was ordained by him and sent to Gaul (France) to preach the Gospel and assist another of Polycarp's disciples, St. Pothinus. Pothinus was the first Bishop of Lyons. After his martyrdom, Irenaeus was made Bishop. He was a staunch defender of the Faith against heretics. He wrote many treatises expounding Orthodox faith. He was martyred along with 19,000 others in 202 under Emperor Severus.
Thou hast shown thyself, O God inspired Irenaeus as a guide to the Orthodox Faith, a teacher of true worship and purity, O star of the universe and companion of Bishops, O wise one. Through thy light thou hast enlightened all, O harp of the Spirit. Therefore, intercede with Christ God to save our souls.