The Aramaeans of the Third Semitic migration were not slow to take advantage of the weakness of Assyria and Babylon.  They overran the whole of Syria, and entered into the possession of Mesopotamia, thus acquiring full control of the trade routes towards the west.  From time to time they ravaged Babylonia from the north to the south.  Large numbers of them acquired permanent settlement in that country, like the Amorites of the Second Semitic migration in the pre-Hammurabi Age.

In Syria the Aramaeans established several petty States, and were beginning to grow powerful at Damascus, an important trading centre, which assumed considerable political importance after the collapse of Assyria’s Old Empire.

At this period, too, the Chaldaeans came into prominence in Babylonia.  Their kingdom of Chaldaea (Kaldu, which signifies Sealand) embraces a wide stretch of the coast land at the head of the Persian Gulf between Arabia and Elam.  As we have seen, an important dynasty flourished in this region in the time of Hammurabi.  Although more than one king of Babylon recorded that he had extinguished the Sealand Power, it continued to exist all through the Kassite period.  It is possible that this obscure kingdom embraced diverse ethnic elements, and that it was controlled in turn by military aristocracies of Sumerians, Elamites, Kassites, and Arabians.  After the downfall of the Kassites it had become thoroughly Semitized, perhaps as a result of the Aramaean migration, which may have found one of its outlets around the head of the Persian Gulf.  The ancient Sumerian city of Ur, which dominated a considerable area of steppe land to the west of the Euphrates, was included in the Sealand kingdom, and was consequently referred to in after-time as “Ur of the Chaldees”.

When Solomon reigned over Judah and Israel, Babylonia was broken up into a number of petty States, as in early Sumerian times.  The feudal revival of Nebuchadrezzar I had weakened the central power, with the result that the nominal high kings were less able to resist the inroads of invaders.  Military aristocracies of Aramaeans, Elamites, and Chaldaeans held sway in various parts of the valley, and struggled for supremacy.

When Assyria began to assert itself again, it laid claim on Babylonia, ostensibly as the protector of its independence, and the Chaldaeans for a time made common cause with the Elamites against it.  The future, however, lay with the Chaldaeans, who, like the Kassites, became the liberators of the ancient inhabitants.  When Assyria was finally extinguished as a world power they revived the ancient glory of Babylonia, and supplanted the Sumerians as the scholars and teachers of Western Asia.  The Chaldaeans became famous in Syria, and even in Greece, as “the wise men from the east”, and were renowned as astrologers.