This bold scheme, however, was foredoomed to failure.  It was shown scant favour by the Babylonian Kassites.  No record survives to indicate the character of the agreement between Kadashman-Kharbe and Ashur-uballit, but there can be little doubt that it involved the abandonment by Babylonia of its historic claim upon Mesopotamia, or part of it, and the recognition of an Assyrian sphere of influence in that region.  It was probably on account of his pronounced pro-Assyrian tendencies that the Kassites murdered Kadashman-Kharbe, and set the pretender, known as “the son of nobody”, on the throne for a brief period.

Kadashman-Kharbe’s immediate successors recognized in Assyria a dangerous and unscrupulous rival, and resumed the struggle for the possession of Mesopotamia.  The trade route across the Arabian desert had to be abandoned.  Probably it required too great a force to keep it open.  Then almost every fresh conquest achieved by Assyria involved it in war with Babylonia, which appears to have been ever waiting for a suitable opportunity to cripple its northern rival.

But Assyria was not the only power which Babylonia had to guard itself against.  On its eastern frontier Elam was also panting for expansion.  Its chief caravan roads ran from Susa through Assyria towards Asia Minor, and through Babylonia towards the Phoenician coast.  It was probably because its commerce was hampered by the growth of Assyrian power in the north, as Servia’s commerce in our own day has been hampered by Austria, that it cherished dreams of conquering Babylonia.  In fact, as Kassite influence suffered decline, one of the great problems of international politics was whether Elam or Assyria would enter into possession of the ancient lands of Sumer and Akkad.

Ashur-uballit’s vigorous policy of Assyrian expansion was continued, as has been shown, by his son Bel-nirari.  His grandson, Arik-den-ilu, conducted several successful campaigns, and penetrated westward as far as Haran, thus crossing the Babylonian caravan road.  He captured great herds of cattle and flocks of sheep, which were transported to Asshur, and on one occasion carried away 250,000 prisoners.

Meanwhile Babylonia waged war with Elam.  It is related that Khur-batila, King of Elam, sent a challenge to Kurigalzu III, a descendant of Kadashman-Kharbe, saying:  “Come hither; I will fight with thee”.  The Babylonian monarch accepted the challenge, invaded the territory of his rival, and won a great victory.  Deserted by his troops, the Elamite king was taken prisoner, and did not secure release until he had ceded a portion of his territory and consented to pay annual tribute to Babylonia.

Flushed with his success, the Kassite king invaded Assyria when Adad-nirari I died and his son Arik-den-ilu came to the throne.  He found, however, that the Assyrians were more powerful than the Elamites, and suffered defeat.  His son, Na’zi-mar-ut’tash[409], also made an unsuccessful attempt to curb the growing power of the northern Power.