Diatessaron

thumb|Parchment manuscript of the Ephrem's Commentary on the Diatessaron, from Egypt, late 5th or early 6th century, in the [[Chester Beatty Library]]

The Diatessaron (; c. 160–175 AD) is the most prominent early gospel harmony. It was created in the Syriac language by Tatian, an Assyrian early Christian apologist and ascetic. Tatian sought to combine all the textual material he found in the four gospels – Matthew, Mark, Luke, and John – into a single coherent narrative of Jesus's life and death. However, and in contradistinction to most later gospel harmonists, Tatian appears not to have been motivated by any aspiration to validate the four separate canonical gospel accounts; or to demonstrate that, as they stood, they could each be shown as being without inconsistency or error.