The countries by which the Babylonian Empire was bounded were Persia on the east, Media and her dependencies on the north, Arabia on the south, and Egypt at the extreme southwest.  Directly to the west she had no neighbor, her territory being on that side washed by the Mediterranean.

Of Persia, which must be described at length in the next volume, since it was the seat of Empire during the Fifth Monarchy, no more need be said here than that it was for the most part a rugged and sterile country, apt to produce a brave and hardy race, but incapable of sustaining a large population.  A strong barrier separated it from the great Mesopotamian lowland; and the Babylonians, by occupying a few easily defensible passes, could readily prevent a Persian army from debouching on their fertile plains.  On the other hand, the natural strength of the region is so great that in the hands of brave and active men its defence is easy; and the Babylonians were not likely, if an aggressive spirit led to their pressing eastward, to make any serious impression in this quarter, or ever greatly to advance their frontier.

To Media, the power which bordered her upon the north, Babylonia, on the contrary, lay wholly open.  The Medes, possessing Assyria and Armenia, with the Upper Tigris valley, and probably the Mons Masius, could at any time, with the greatest ease, have marched armies into the low country, and resumed the contest in which Assyria was engaged for so many hundred years with the great people of the south.  On this side nature had set no obstacles; and, if danger threatened, resistance had to be made by means of those artificial works which are specially suited for flat countries.  Long lines of wall, broad dykes, huge reservoirs, by means of which large tracts may be laid under water, form the natural resort in such a case; and to such defences as these alone, in addition to her armies, could Babylonia look in case of a quarrel with the Medes.  On this side, however, she for many years felt no fear.  Political arrangements and family ties connected her with the Median reigning house, and she looked to her northern neighbor as an ally upon whom she might depend for aid, rather than as a rival whose ambitious designs were to be watched and baffled.

Babylonia lay open also on the side of Arabia.  Here, however, the nature of the country is such that population must be always sparse; and the habits of the people are opposed to that political union which can alone make a race really formidable to others.  Once only in their history, under the excitement of a religious frenzy, have the Arabs issued forth from the great peninsula on an errand of conquest.  In general they are content to vex and harass without seriously alarming their neighbors.  The vast space and arid character of the peninsula are adverse to the collection and the movement of armies; the love of independence cherished by the several tribes indisposes them to union; the affection for the nomadic