Irenaeus of Lyons

Overview - Irenaeus of Lyons

Irenaeus of Lyons wrote his Against Heresies c. 175-185 CE. His work is invaluable to modern scholarship in the attempt to recover the content of Gnostic teachings in the second century. Irenaeus also provides the first explicit witness to a four-fold gospel canon. 

References

https://www.earlychristianwritings.com/irenaeus.html