Irenaeus of Lyons

Bishop of Lyons, who wrote against the Gnostics and defended the faith handed down from the apostles.

c. AD 130–202 Greek East The third century 5 works Wikipedia

Fully prepared texts

Side by side with the original Greek where we have it, an older public-domain English translation, and a modern English version.

Against Heresies Older English 168 chapters

More writings in English

English translations (older public-domain ones, and a few modern ones shared under open licences), divided into chapters and short sections, with a download for each. A modern English version and the original-language text are planned for the works that matter most.

Fragments from the Lost Writings of Irenaeus Older English 35 min read
The Proof of the Apostolic Preaching Older English 2.0 h read

Original-language texts

The Latin and Greek texts as edited and digitised by the Open Greek and Latin project (CC BY-SA 4.0): one column, with the standard references, and plain-text and TEI XML downloads for scholars. They have been corrected from print by machine and may still contain errors.

Fragmenta Synodicae Epistulae. (Greek) Greek 2 min read
Libros quinque adversus haereses (Greek) Greek 1.6 h read

Most translations are the older ones in the public domain (mostly the nineteenth-century Ante-Nicene, Nicene and Post-Nicene Fathers); a few are modern translations shared under an open licence, with the translators credited on the work’s page. Square brackets and any Greek or Latin words are as the source prints them.