The History of Antiquity Volume II: Assyria, Phoenicia and Israel

About the middle course of the Tigris, where the mountain wall of the Armenian plateau steeply descends to the south, there is a broad stretch of hilly country. To the west it is traversed by a few water-courses only, which spring out of the mountains of Sindyar, and unite with the Tigris; from the east the affluents are far more abundant. On the southern shore of the lake of Urumiah the edge of the plateau of Iran abuts on the Armenian table-land, and then, stretching to the south-east, it bounds the river valley of the Tigris toward the east. From its vast, successive ranges, the Zagrus of the Greeks, flow the Lycus and Caprus (the Greater and the Lesser Zab), the Adhim and the Diala. The water, which these rivers convey to the land between the Zagrus and the Tigris, together with the elevation of the soil, softens the heat and allows olive trees and vines to flourish in the cool air on the hills, sesame and corn in the valleys between groups of palms and fruit-trees. The backs of the heights which rise to the east are covered by forests of oaks and nut trees. Toward the south the ground gradually sinks—on the west immediately under the mountains of Sindyar, on the east below the Lesser Zab—toward the course of the Adhim into level plains, where the soil is little inferior in fertility to the land of Babylonia. The land between the Tigris and the Greater Zab is known to Strabo and Arrian as Aturia.The districts between the Greater and Lesser Zab are called Arbelitis and Adiabene by western writers. The region bounded by the Lesser Zab and the Adhim or the Diala is called Sittacene, and the land lying on the mountains rising further toward the east is Chalonitis. The latter we shall without doubt have to regard as the Holwan of later times. 

According to the accounts of the Greeks, it was in these districts that the first kingdom rose which made conquests and extended its power beyond the borders of its native country...