Above the junction of the Khabour with the main stream, the left bank is mostly cultivable.

Much of the land is flat and well-wooded, while often there are broad stretches of open ground, well adapted for pasturage.

A considerable population seems in ancient times to have peopled the valley, which did not depend wholly or even mainly on its own products, but was enriched by the important traffic which was always passing up and down the great river.
Mesopotamia Proper, or the tract extending from the head streams of the Khabour about Mardin and Nisibin to the Euphrates at Bir, and thence southwards to Karkesiyeh or Circesium, is not certainly known to have belonged to the kingdom of Babylon, but may be assigned to it on grounds of probability.

Divided by a desert or by high mountains from the valley of the Tigris, and attached by means of its streams to that of the Euphrates, it almost necessarily falls to that power which holds the Euphrates under its dominion.

The tract is one of considerable extent and importance.