The earliest agriculturists and traders of Babylonia were the Sumerians, a non-Semitic people, who built a number of cities in the irrigated valley and founded colonies in Assyria. No trace has been found of a Neolithic Age in Babylonia. Its civilization, so far as our knowledge goes, began after copper was introduced. At an early period Semites filtered into the valley. They absorbed Sumerian civilization, and ultimately became politically predominant in the northern part of the valley, which was called Akkad (the biblical Accad). The southern part was then known as Sumer or Sumeria (the biblical 'Plain of Shinar'). Akkad embraced the city States of Agade, Babylon, Borsippa, Sippar, Kish, Opis, and Kutha. The Sumerian city States included Eridu, Ur (later 'of the Chaldees' and the birthplace of Abraham), Lagash, Shuruppak, Erech, Umma, and Adab. Inter-state wars resulted time and again in the formation of confederacies which were more of political than racial character, and the predominance of one city or another. Religious ideas were fused, and local pantheons appear to have reflected local politics. The chief seat of early Sumerian civilization was the city of Eridu, a name signifying 'on the seashore'. Its site is marked by modern Abu-Shahrein on the eastern bank of the Euphrates, and south-east of Ur, modern Mukayyar. Eridu was originally a seaport on the Persian Gulf, from which it is now separated by about 125 miles of land formed by river silt. The chief god of Eridu was Ea, a name also rendered Ae and Aa, and apparently meaning 'waters' or 'house (region) of waters'. That the term 'waters' had a special significance for the inhabitants of a water-formed land is evident by the fact that the Semitic equivalent of Ea is Enki, which means 'lord of earth'. Other titles of the god were 'lord of Heaven and Earth', 'ruler of the land', 'the deep', 'god of the abyss', and 'king of the river'. He was withal the 'Creator', water having created Sumeria, and Nadimmud, 'lord of everything', as the Egyptian Osiris in his character of god of the Nile was 'Neb-er-Zer', also 'lord of everything'. Ea had a ship with a crew including his son Marduk (Merodach or Marad, the Ni-marad or Nimrod of legend) and In-ab, 'the pilot of Eridu'. The ship was hailed, in religious literature, as the bringer of fertility and joy. Evidently the beginning of Sumerian civilization had some connection with ancient seafarers. Of special interest in this connection are the references made by the Greek writer Berosus to Oannes, a sea-dweller who came daily from the Persian Gulf to instruct the early Babylonians how to irrigate the land, grow crops, erect houses, make laws, write, calculate and measure, and engage in trade. Texts have been discovered which tend to identify Oannes with the god Ea. As the early Sumerians bore a strong physical resemblance to the ancient Egyptians, and there were links between the early religious beliefs and customs of the two peoples, it is suspected that they represented two branches of the same ancient stock. Some think Sumerian civilization was founded by colonists from Egypt, while others believe that Egyptian civilization was stimulated by settlers from Sumeria. The question as to who first invented ships has an important bearing in this connection. When we turn to Sumero-Babylonian religious myths we find that some reflect local natural phenomena. In one the Euphrates is hailed as the River (god) "who didst create all things". Another, referring to the creation of man, says that Marduk (earlier the god Gilimma) "tied reeds on the face of the waters, he formed dust and poured it out beside the reeds ... he formed mankind". Another version is that man was created from the god's blood and bone, or, as Berosus has it, from the god's blood and earth. The oldest Sumerian creation myth states that all things came from primeval water. Then many deities were created by the pre-existing triad of gods, Anu (the sky-god), Enlil ('the elder Bel', the earth-god, and 'lord of grain'), and Ea, who was associated with the goddess Ninkharsagga. Ea had several other wives, including Ninshar or Ninkurra, Ninella, Nintu, and Damkina. These goddesses were ultimately all absorbed by Ishtar, the Semitic name of the love and mother goddess. In the later Babylonian 'Seven Tablets' version of the creation myth a conflict is introduced. The female chaos-dragon Tiamat is slain by Marduk, the chief god of Babylon, 'the later Bel', who cuts up her body and uses part to form the sky and part to keep the waters in their place. After a time a deluge took place.