If Assyria be allowed the extent which is here assigned to her, she will be a country, not only very much larger than Chaldaea or Babylonia, but positively of considerable dimensions.  Reaching on the north to the thirty-eighth and on the south to the thirty-fourth parallel, she had a length diagonally from Diarbekr to the alluvium of 350 miles, and a breadth between the Euphrates and Mount Zagros varying from about 300 to 170 miles.  Her area was probably not less than 75,000 square miles, which is more than double that of Portugal, and not much below that of Great Britain.  She would thus from her mere size be calculated to play an important (part) in history; and the more so, as during the period of her greatness scarcely any nation with which she came in contact possessed nearly so extensive a territory.

Within the limits here assigned to Assyria, the face of the country is tolerably varied.  Possessing, on the whole, perhaps, a predominant character of flatness, the territory still includes some important ranges of hills, while on the two sides it abuts upon lofty mountain-chains.  Towards the north and east it is provided by nature with an ample supply of water, rills everywhere flowing from the Armenian and Kurdish ranges, which soon collect into rapid and abundant rivers.  The central, southern, and western regions are, however, less bountifully supplied; for though the Euphrates washes the whole western and south-western frontier, it spreads fertility only along its banks; and though Mount Masius sends down upon the Mesopotamian plain a considerable number of streams, they form in the space of 200 miles between Balls and Mosul but two rivers, leaving thus large tracts to languish for want of the precious fluid.  The vicinity of the Arabian and Syrian deserts is likewise felt in these regions, which, left to themselves, tend to acquire the desert character, and have occasionally been regarded as actual parts of Arabia.

The chief natural division of the country is that made by the Tigris, which, having a course nearly from north to south, between Til and Samarah, separates Assyria into a western and an eastern district.  Of these two, the eastern or that upon the left bank of the Tigris, although considerably the smaller, has always been the more important region.  Comparatively narrow at first, it broadens as the course of the river is descended, till it attains about the thirty-fifth parallel a width of 130 or 140 miles.  It consists chiefly of a series of rich and productive plains, lying along the courses of the various tributaries which flow from Mount Zagros into the Tigris, and often of a semi-alluvial character.  These plains are not, however, continuous.  Detached ranges of hills, with a general direction parallel to the Zagros chain, intersect the flat rich country, separating the plains from one another, and supplying small streams and brooks in addition to the various rivers, which, rising within or beyond the great mountain barriers,