During chaos the god Tiamat decides to kill younger Gods Ea, Enki and the others becasue they were very loud. At the end God Marduk defeats Tiamat. After his win he is declared as the leader of the Gods and followingly they begin to create humanity. It somehow represent a rivalry between the cosmic order and chaos.
Enuma Elish from the point of view of some historians accepted as the root of Book of Genesis as there are many similarities between two of them. The epic has first been published by George Smith in 1876, Chaldean Genesis.
Quotation from the first tablet:
When in the height heaven was not named,
And the earth beneath did not yet bear a name,
And the primeval Apsu, who begat them,
And chaos, Tiamut, the mother of them both
Their waters were mingled together,
And no field was formed, no marsh was to be seen;
When of the gods none had been called into being,
And none bore a name, and no destinies were ordained;
Then were created the gods in the midst of heaven,
Lahmu and Lahamu were called into being...