The settlement of the Kaldâ 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 Kaldâ 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 Chaldæa 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.

The small states of Babylonia were constantly at war with each other, even though they shared in a common civilisation, worshipped the same gods, and presented their offerings to the same sanctuary of Nippur. Southern Babylonia—or Kengi, "the land of canals and reeds," as it was often named—was already divided against the north. At times it exercised supremacy as far as Nippur. En-sakkus-ana of Kengi conquered Kis, like one of his predecessors who had dedicated the statue, the store of silver, and the furniture of the conquered prince to Mul-lil. Kis claimed sovereignty over the Bedâwin "archers," who had their home in the district now called Jokha. But Kis eventually revenged itself. One of its rulers made himself master of Nippur, and the kingdom of Kengi passed away. The final blow was struck by Lugal-zaggi-si, the son of the high-priest of the city of Opis. Lugal-zaggi-si not only conquered Babylonia, he also created an empire. On the vases of delicately-carved stone which he dedicated to the god of Nippur, a long inscription of one hundred and thirty-two lines describes his deeds, and tells how he had extended his dominion from the Persian Gulf to the Mediterranean Sea. It may be that at this time the culture of Babylonia was first brought to the west, and that his conquests first communicated a knowledge of the Sumerian language and writing to the nations of western Asia. With the spoils of his victories the walls of Ur were raised "high as heaven," and the temple of the Sun-god at Larsa was enlarged. Erech was made his capital, and doubtless now received its Sumerian title of "the City" par excellence.

The dynasty of Erech was supplanted by the First dynasty of Ur. Erech was captured by Lugal-kigub-nidudu of Ur, and took the second rank in the new kingdom. The position of Ur on the western bank of the Euphrates exposed it to the attacks of the Semitic tribes of northern Arabia, and thus accustomed its inhabitants to the use of arms, while at the same time its proximity to Eridu made it a centre of trade. In Abrahamic days it had long been a place of resort and settlement by Arabian and Canaanite merchants.

How long the supremacy of Ur lasted we do not know. Nor do we know whether it preceded or was followed by the supremacy of Lagas. The kings of Lagas had succeeded in overcoming their hereditary enemies to the north. The so-called "Stela of the Vultures," now in the Louvre, commemorates the overthrow of the forces of the land of Upe or Opis, and depicts the bodies of the slain as they lie on the battlefield devoured by the birds of prey. E-ana-gin, the king of Lagas who erected it, never rested until he had subjected the rest of southern Babylonia to his sway. The whole of "Sumer" was subdued, and the memory of a time when a king of Kis, Mesa by name, had subjected Lagas to his rule, was finally wiped out.

High-priests now took the place of kings in Kis and the country of Opis. But a time came when the same change occurred also at Lagas. doubtless in consequence of its conquest by some superior power. One of the monuments discovered at Tello, the ancient Lagas, describes the victories of the "high-priest" Entemena over the ancestral foe, and the appointment of a certain Ili as "high-priest" of the land of Opis. From henceforward Kis and Opis disappear from history.

A new power had meanwhile appeared on the scene. While the Sumerian princes were engaged in mutual war, the Semites were occupying northern Babylonia, and establishing their power in the city of Agadê or Akkad, not far from Sippara. Here, in B.C. 3800, arose the empire of Sargani-sar-ali, better known to posterity as "Sargon" of Akkad. He became the hero of the Semitic race in Babylonia. Legends told how he had been hidden by his royal mother in an ark of bulrushes daubed with pitch, and intrusted to the waters of the Euphrates, how he had been found and adopted as a son by Akki the irrigator, and how the goddess Istar had loved him and restored him to his kingly estate. At all events, the career of Sargon was a career of victories. Babylonia was united under his rule, Elam was subjugated, and three campaigns sufficed to make "the land of the Amorites," Syria and Canaan, obedient to his sway. He caused an image of himself to be carved on the shores of the Mediterranean, and demanded tribute from Cyprus, Uru-Malik or Urimelech being appointed governor of Syria, as we learn from a cadastral survey of the district of Lagas. A revolt of the Sumerian states, however, called him home, and for a time fortune seemed against him. He was besieged in Akkad, but a successful sally drove back the rebels, and they were soon utterly crushed. Then Sargon marched into Suri or Mesopotamia, subduing that country as well as the future Assyria. It was the last, however, of his exploits. His son Naram-Sin succeeded him shortly afterwards (B.C. 3750), and continued the conquests of his father, Canaan was already a Babylonian province, and Naram-Sin now carried his arms against Magan, or the Sinaitic Peninsula, where he secured the precious mines of copper and turquoise. Building stone from Magan had already been imported to Babylonia by Ur-Nina, a king of Lagas, and grandfather of E-ana-gin, but it must have been brought in the ships of Eridu.