Marduk, literally meaning 'bull calf of the sun' and son of Ea, apparently was a god of magic and incantations from early times. This double-headed sun god was given the epithet Bel, "lord" and identified with Enlil, especially he assumed the leadership of the Babylonian pantheon during the cosmic struggle with Tiamat, the sea-dragon of the salt-water ocean; therefore, he naturally became the telary god of the city of Babylon. After defeating Tiamat he split her in two halves, one half from which he formed the heaven and the other half the earth. After doing this he fastened the badge of destiny upon his breast, creating a new world order including humankind. This is a paradoxical creation myth: for the chaos-monster, though slain and dismembered remained the body of the universe and was manifest in her children, the gods and goddesses from whom Bel-Marduk received homage.
In the mythology of the creation epic, Marduk wages a primordial cosmic battle with Tiamat, the power of the ocean. He kills her, splitting her in half, and uses her body parts to make heaven and earth. Tiamat fought him in revenge for the death of Apsu, the deep, and is reported to have created an exact replica of Apsu, the Esarra.
The mar, a Mesopotamian agricultural tool, triangular shaped, is the symbol of Marduk. His main festival, the akitu, also was celebrated at New Year till about 200 BCE; the Persian rule Cambyses performed it around 538 BCE. In Babylon Marduk's sanctuary is at the Esagila and the E-temen-anki ziggurat.
His consort was the goddess Tasmetu(m) with whom his marriage was reenacted as an annual New Year festival. Others say his consort was Sarpanitu.With the changing of the imperial reigns Marduk lost prominence and eventually regained it by taking over the role of An and replacing Enlil. In the Assyrian takeover Marduk was replaced with Ashur. A.G.H.
Cotterell, Arthur, A Dictionary of World Mythology, New York, G. P. Putman's Sons, 1980, p. 38
Jordan, Michael, Encyclopedia of Gods, New York, Facts On File, Inc. 1993, pp. 157-158