2nd century Bishop of Lyon, then in Gaul.
At that time, a multitude of different Christianities, with Gnosticism an important force.  In his work, “Against Heresies”, he emphasized the unbroken chain from the apostles through the bishops, eg the Roman church, and the 4 Gospels as being the core scripture of Christianity, in addition to the Old Testament.
This was in contrast to the secret, oral traditions and various texts held sacred by some Gnostic churches, and theologians such as Marcion, who felt the Judaic God, and the Old testament in general, as being incompatible with the message of Jesus.