In the south the Tigris and Euphrates made their way to the region of salt-marshes, called Marratu in the inscriptions, Merathaim by the prophet Jeremiah.  They were inhabited by the Semitic tribe of the Kalda, whose princes owned an unwilling obedience to the Babylonian kings.  One of them, Merodach-baladan, succeeded in making himself master of Babylonia, and from that time forward the Kalda became so integral a part of the population as eventually to give their name to the whole of it.  For the writers of Greece and Rome the Babylonians are Chaldaeans.  It is probable that Nebuchadrezzar was of Kalda origin; if so, this would have been a further reason for the extension of the tribal name to the whole country.

The settlement of the Kalda in the marshes was of comparatively late date.  Indeed, in the early age of Babylonian history these marshes did not as yet exist; it was not until Eridu had ceased to be a seaport that they were reclaimed from the sea.  The Kalda were the advance-guard of the Nabatheans and other Aramaic tribes of northern Arabia, who migrated into Babylonia and pitched their tents on the banks of the Euphrates, first of all as herdsmen, afterwards as traders.  After the fall of the Babylonian monarchy their numbers and importance increased, and the Aramaic they spoke—­the so-called “Chaldee”—­came more and more to supersede the language of Babylonia.

When first we get a glimpse of Babylonian history, the country is divided into a number of small principalities.  They are all Sumerian, and among them the principality of Kish occupies a leading place.  The temple of Mul-lil at Nippur is the central sanctuary, to which they bring their offerings, and from which a civilising influence emanates.  It is an influence, however, which reflects the darker side of life.  Mul-lil was the lord of the dead; his priests were sorcerers and magicians, and their sacred lore consisted of spells and incantations.  Supplementing the influence of Nippur, and in strong contrast with it, was the influence of Eridu.  Ea or Oannes, the god of Eridu, was a god who benefited mankind.  He was the lord of wisdom, and his wisdom displayed itself in delivering men from the evils that surrounded them, and in teaching them the arts of life.  But he was lord also of the water, and it was told of him how he had arisen, morning after morning, from the depths of the Persian Gulf, and had instructed the people of Chaldaea in all the elements of civilisation.  Eridu was the home of the hymns that were sung to the gods of light and life, and which came to be looked upon as divinely inspired.

It is clear that the myth of Cannes points to foreign intercourse as the ultimate cause of Babylonian culture.  It is natural that such should have been the case.  Commerce is still the great civiliser, and the traders and sailors of Eridu created tastes and needs which they sought to satisfy.