Ante-Nicene

Bishop of Lyons, disciple of Polycarp, and author of Against Heresies, the foundational anti-Gnostic work. Bridge between apostolic and ante-Nicene eras.

Successor to Pantaenus at the Catechetical School of Alexandria. Author of Protrepticus, Paedagogus, and Stromateis. Teacher of Origen.

First major Latin Christian author; coined much of Western theological vocabulary (trinitas, persona, substantia). Apologeticus, Adv. Marcionem, De Praescriptione. Later joined the New Prophecy (Montanism).

Roman presbyter (and possibly antipope) who wrote the Refutation of All Heresies and the Apostolic Tradition. Exiled to Sardinia under Maximinus Thrax. Some scholars split this figure into two; tradition treats him as one.