When Babylon became the capital of Mesopotamia, the patron deity of Babylon was elevated to the level of supreme god. In order to explain how Marduk seized power, Enûma Elish was written, which tells the story of Marduk's birth, heroic deeds and becoming the ruler of the gods. This can be viewed as a form of Mesopotamian apologetics. Also included in this document are the fifty names of Marduk.
In Enûma Elish, a civil war between the gods was growing to a climactic battle. The Anunnaki gods gathered together to find one god who could defeat the gods rising against them. Marduk, a very young god, answered the call and was promised the position of head god.
To prepare for battle, he makes a bow, fletches arrows, grabs a mace, throws lightning before him, and fills his body with flame. Then he sets out for battle, mounting his storm-chariot drawn by four horses with poison in their mouths. In his lips he holds a spell and in one hand he grasps a herb to counter poison.
First, he challenges the leader of the Anunnaki gods, the dragon of the primordial sea Tiamat, to single combat and defeats her by trapping her with his net, blowing her up with his winds, and piercing her belly with an arrow.
Then, he proceeds to defeat Kingu, who Tiamat put in charge of the army and wore the Tablets of Destiny on his breast, and "wrested from him the Tablets of Destiny, wrongfully his" and assumed his new position. Under his reign humans were created to bear the burdens of life so the gods could be at leisure.
Marduk was depicted as a human, often with his symbol the snake-dragon which he had taken over from the god Tishpak. Another symbol that stood for Marduk was the spade.
Babylonian texts talk of the creation of Eridu by the god Marduk as the first city, "the holy city, the dwelling of their [the other gods] delight".
Nabu, god of wisdom, is a son of Marduk.