In Edessa this dialect was employed as a literary language, certainly long before the introduction of Christianity. But it attained special importance, from the time the Bible was translated into it (probably in the 2nd century) and Edessa became more and more the capital of purely Aramaic Christianity (in a different fashion from the semi-Greek Antioch). With Christianity the language of Edessa pushed its way even into the kingdom of Persia. By the 4th century, as being then Syriac pure and simple, it serves (and that exclusively) the Aramaean Christians on the Tigris as their literary language. During that period, so far as we know, it was only in Palestine that a local Aramaic dialect was—to a certain extent—made use of by Christians, for literary purposes. The Syriac writings of the heathen of Harrān, the neighbouring city to Edessa,-—of which writings, unfortunately, nothing has been preserved for us—, must have exhibited but a trifling difference at the most from those of the Christians.
The language and its orthography already present such a settled appearance in the excellent manuscripts of the 5th century, that we can hardly doubt that scholastic regulation was the main factor in improving the popular tongue into the literary one. The Greek model has been effective here. The influence of Greek is shown directly, not merely in the intrusion of many Greek words, but also in the imitation of the Greek use of words, Greek idiom and Greek construction, penetrating to the most delicate tissues of the language. Numerous translations and imitations (such as the treatise on Fate, composed after Greek patterns by a pupil of, about the beginning of the 3rd century) furthered this process. But we must carefully distinguish between Greek elements which had made good their entry into the language, and such Graecisms as must have been forced upon it by pedantic translators and imitators. Many Hebraisms also found their way into Syriac through the old translations of the Bible, in which Jewish influence operated strongly.
The golden age of Syriac reaches to the 7th century. The Syrians of that day belonged partly to the Roman empire, and partly to the Persian. The cleavage was made more pronounced by the ecclesiastical divisions, occasioned specially by the unhappy Christological controversies.