Development of the New Testament canon a novelty in Irenaeus's time. "Against Heresies" 3.11.7 acknowledges that many heterodox Christians use only one gospel while 3.11.9 acknowledges that some use more than four. The success of Tatian's Diatessaron in about the same time period is "...a powerful indication that the fourfold Gospel contemporaneously sponsored by Irenaeus was not broadly, let alone universally, recognized." Irenaeus apparently quotes from 21 of the New Testament books and names the author he thought wrote the text. He mentions the four gospels, Acts, the Pauline epistles with the exception of Hebrews and Philemon, as well as the first epistle of Peter, and
Rossano Gospels small Old Testament prophet portraits below, prefiguring and pointing up to events described in the New Testament scene above. The now incomplete codex contains the text of the Gospel of Matthew and the majority of the Gospel of Mark, with only one lacuna (Mark 16:14-20). Probably it had companion second volume which is apparently lost. Like the Vienna Genesis and the Sinope Gospels, the Rossano Gospels are written in silver ink on purple dyed parchment. The large ( by ) book has text written in a square block with two columns of twenty lines each. There is a prefatory cycle