St. Irenaeus of Lyons (c. 125 - 203 A.D.) was born in Asia Minor at a time when the direct memory of the Apostles was still alive. He was well educated in Sacred Scripture, theology, philosophy, and literature. He became an astute disciple of St. Polycarp, who himself was a disciple of St. John the Evangelist, one of the Twelve Apostles who belonged to Jesus' inner circle. St. Irenaeus is therefore an early witness of the authentic teaching of the Apostles preserved and handed down in both the written and oral tradition. St. Irenaeus was ordained a priest and became bishop of Lyons in modern-day France. He was one of the Church's first great theologians and apologists, writing his famous and important work 'Against Heresies' to combat the heresy of Gnosticism which greatly threatened the early Church. He is also an early witness of the primacy of Peter over the other Apostles, and thus the authority of the Roman See over the whole Church. St. Irenaeus is one of the most important early Church Fathers and is a Doctor of the Church. His feast day is June 28.