"Before Irenaeus, Christians differed as to which gospel they preferred. The Christians of Asia Minor preferred the Gospel of John. The Gospel of Matthew was the most popular overall.[37] Irenaeus asserted that four Gospels, Matthew, Mark, Luke, and John, were canonical scripture.[38] Thus Irenaeus provides the earliest witness to the assertion of the four canonical Gospels, possibly in reaction to Marcion's edited version of the Gospel of Luke, which Marcion asserted was the one and only true gospel.[6][25]
"Based on the arguments Irenaeus made in support of only four authentic gospels, some interpreters deduce that the fourfold Gospel must have still been a novelty in Irenaeus' time.[39] 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.
https://en.wikipedia.org/wiki/Irenaeus