Best known for his harmony of the four gospels (Diatessaron), Tatian is usually remembered in the Western Church (but not in all portions of the Eastern Church) as a Christian apologist turned heretic. He was born in Assyria (or Syria) ca. 120 CE and came to Rome, where he adopted the Christian way through reading "barbarian writings" (Jewish Scripture, Or 29:1). There he became a student of Justin Martyr, after whose death (ca. 163-167) he returned to his birthplace in 172 CE. Almost nothing is known of his later life in Syria (d. ca. 180-190).
Yinger, Kent, "Tatian" (2010). Faculty Publications - Portland Seminary. 157.