Tatian was an Assyrian who was a pupil of Justin Martyr in Rome, where, Justin says, the apomnemoneumata (recollections or memoirs) of the Apostles, the gospels, were read every Sunday. When Justin quotes the synoptic Gospels, he tends to do so in a harmonised form, and Helmut Koester and others conclude that Justin must have possessed a Greek harmony text of Matthew, Luke and Mark. If so, it is unclear how much Tatian may have borrowed from this previous author in determining his own narrative sequence of Gospel elements. It is equally unclear whether Tatian took the Syriac Gospel texts composited into his Diatessaron from a previous translation, or whether the translation was his own. Where the Diatessaron records Gospel quotations from the Jewish Scriptures, the text appears to agree with that found in the Syriac Peshitta Old Testament rather than that found in the Greek Septuagint as used by the original Gospel authors.