Most immediately, they have grown out of Eastern Aramaic colloquial varieties that were spoken in the Tur Abdin region and the surrounding plains for a thousand years. However, they have been influenced by Classical Syriac, which itself was the variety of Eastern Aramaic spoken farther west, in the Osroenian city of Edessa. Perhaps the proximity of Central Neo-Aramaic to Edessa, and the closeness of their parent languages, meant that they bear a greater similarity to the classical language than do Northeastern Neo-Aramaic varieties.