In one direction only was Assyria confronted by a rival state pomsessing a power and organization in character not unlike her own, though scarcely of equal strength.

On her southern frontier, in the broad flat plain intervening between the Mesopotamian upland and the sea--the kingdom of Babylon was still existing; its Semitic kings, though originally established upon the throne by Assyrian influence, had dissolved all connection with their old protectors, and asserted their thorough independence.

Here, then, was a considerable state, as much centralized as Assyria herself, and not greatly inferior either in extent of territory or in population, existing side by side with her, and constituting a species of check, whereby something like a balance of power was still maintained in Western Asia, and Assyria: was prevented from feeling herself the absolute mistress of the East, and the uncontrolled arbitress of the world's destinies.
Besides the great cylinder inscription of Tiglath-Pileser there exist five more years of his annals in fragments, from which we learn that he continued his aggressive expeditious during this space, chiefly towards the north west, subduing the Lulumi in Northern Syria, attacking and taking Carchemish, and pursuing the inhabitants across the Euphrates in boats.
No mention is made during this time of any collision between Assyria and her great rival.Babylon.The result of the wars waged by Asshur-ris-ilim against Nebuchadnezzar I., had, apparently, been to produce in the belligerents a feeling of mutual respect; and Tiglath-Pileser, in his earlier years, neither trespassed on the Babylonian territory in his aggressive raids, nor found himself called upon to meet and repel any invasion of his own dominions by his southern neighbors.

Before the close of his reign, however, active hostilities broke out between the two powers.

Either provoked by some border ravage or actuated simply by lust of conquest, Tiglath-Pileser marched his troops into Babylonia.