Taking advantage of the circumstance that a civil war was raging in Babylonia between the legitimate monarch Merodach-sum-adin, and his young brother, he marched into the country, took a number of the towns, and having defeated and slain the pretender, was admitted into Babylon itself.  From thence he proceeded to overrun Chaldaea, or the district upon the coast, which appears at this time to have been independent of Babylon, and governed by a number of petty kings.  The Babylonian monarch probably admitted the suzerainty of the invader, but was not put to any tribute.  The Chaldaean chiefs, however, had to submit to this indignity.  The Assyrian monarch returned to his capital, having “struck terror as far as the sea.”  Thus Assyrian influence was once more extended over the whole of the southern country, and Babylonia resumed her position of a secondary power, dependent on the great monarchy of the north.

But she was not long allowed to retain even the shadow of an autonomous rule.  In or about the year B.C. 821 the son and successor of the Black-Obelisk king, apparently without any pretext, made a fresh invasion of the country.  Mero-dach-belatzu-ikm, the Babylonian monarch, boldly met him in the field, but was defeated in two pitched battles (in the latter of which he had the assistance of powerful allies) and was forced to submit to his antagonist.  Babylon, it is probable, became at once an Assyrian tributary, and in this condition she remained till the troubles which came upon Assyria towards the middle of the eighth century B.C. gave an opportunity for shaking off the hated yoke.  Perhaps the first successes were obtained by Pul, who, taking advantage of Assyria’s weakness under Asshur-dayan III. (ab.  B.C. 770), seems to have established a dominion over the Euphrates valley and Western Mesopotamia, from which he proceeded to carry his arms into Syria and Palestine.  Or perhaps Pul’s efforts merely, by still further weakening Assyria, paved the way for Babylon to revolt, and Nabonassar, who became king of Babylon in B.C. 747, is to be regarded as the re-establisher of her independence.  In either case it is apparent that the recovery of independence was accompanied, or rapidly followed, by a disintegration of the country, which was of evil omen for its future greatness.  While Nabonassar established himself at the head of affairs in Babylon, a certain Yakin, the father of Merodach-Baladan, became master of the tract upon the coast; and various princes, Nadina, Zakiru, and others, at the same time obtained governments, which they administered in their own name towards the north.  The old Babylonian kingdom was broken up; and the way was prepared for that final subjugation which was ultimately affected by the Sargonids.

Still, the Babylonians seemed to have looked with complacency on this period, and they certainly made it an era from which to date their later history.  Perhaps, however, they had not much choice in this matter.  Nabonassar was a man of energy and determination.  Bent probably on obliterating the memory of the preceding period of subjugation, he “destroyed the acts of the kings who had preceded him;” and the result was that the war of his accession became almost necessarily the era from which subsequent events had to be dated.