The Persians are not mentioned in history before the time of Cyrus; the attempt to identify them with the Parsua, a district in the Zagros chains south of Lake Urmia, often mentioned by the Assyrians, is not tenable.
With such Mesopotamian cities as Nisibis, Amid, Mardin, Taghrith and Seleucia-Ctesiphon, as well as west of the Euphrates at such centres as Mabbogh (Hierapolis, and Aleppo, northwards at Malatiah and Maiperkat and in the districts of Lake Van and Lake Urmia, and to the east and south-east of the Tigris in many places which from the 5th century onwards were centres of Nestorian Christianity within the Sasanian Empire.
- The Nestorians or East Syrians (Surayi) of Turkey and Persia now inhabit a district bounded by Lake Urmia, or Urumia, on the east, stretching westwards into Kurdistan, to Mosul on the south, and nearly as far as Van on the north.
The service-books were wholly in MS. until the press of the archbishop of Canterbury's mission at Urmia issued the Takhsa (containing the liturgies, baptismal office, &c.) and several other liturgical texts.
The American Presbyterian Mission, established in Persia in1834-1835by the Rev. Justin Perkins and Dr A.Grant, comprises large buildings near Urmia, a college and a hospital.