Contributor(s): Author: Tatian The Diatessaron (c 150 - 160) is the most prominent Gospel harmony created by Tatian, an early Christian apologist and ascetic. The term "diatessaron" is from Middle English ("interval of a fourth") by way of Latin, diatessaron ("made of fouringredients]"), and ultimately Greek, diatessaron ("out of four"; i.e., dia, "according to" and tessarongenitive of tessares], "four"). Tatian combined the four gospels - Matthew, Mark, Luke, and John - into a single narrative.