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. Bounded on the north by the range of hills which Strabo
calls Mons Masius, and on the east by the waterless upland which lies
directly west of the middle Tigris, it comprises within it all the
numerous affluents of the Khabour and Bilik, and is thus better supplied
with water than almost any country in these regions. The borders of the
streams afford the richest pasture, and the whole tract along the flank
of Masius is fairly fertile. Towards the west, the tract between the
Khabour and the Bilik, which is diversified by the Abd-el-Aziz hills,
is a land of fountains. "Such," says Ibn Haukal, "are not to be found
elsewhere in all the land of the Moslems, for there are more than three
hundred pure running brooks." Irrigation is quite possible in this
region; and many remains of ancient watercourses show that large tracts,
at some distance from the main streams, were formerly brought under
cultivation.

Opposite to Mesopotamia Proper, on the west or right bank of the
Euphrates, lay Northern Syria, with its important fortress of
Carchemish, which was undoubtedly included in the Empire. This tract is
not one of much value. Towards the north it is mountainous, consisting
of spurs from Amanus and Taurus, which gradually subside into the desert
a little to the south of Aleppo. The bare, round-backed, chalky or rocky
ranges, which here continually succeed one another, are divided only by
narrow tortuous valleys, which run chiefly towards the Euphrates or
the lake of Antioch. This mountain tract is succeeded by a region of
extensive plains, separated from each other by low hills, both equally
desolate. The soil is shallow and stony; the streams are few and of
little volume; irrigation is thus difficult, and, except where it can be
applied, the crops are scanty. The pistachio-nut grows wild in places;
Vines and olives are cultivated with some success; and some grain is
raised by the inhabitants;