Narses on being expelled from Edessa, opened a school at Nisibis, A.D.490, which became celebrated.

About the same time, Acacius, also from Edessa, established a school at Seleucia.

It was revived in 530, and was in existence as late as 605.

A school was established at Dorkena, A.D.585.

At Bagdad were two schools in 832, and two others were in its neighborhood.