Marduk originated as the apotheosis of the biblical Nimrod. The book of Genesis lists Nimrod as a descendant of Ham, the third son of Noah.
After the flood when men began to multiply once again and to establish settlements, the majority of Noah's descendants evidently settled together in the valley of Mesopotamia. After establishing his kingdom in the Tigris/Euphrates region Nimrod consolidated his power by establishing a state religion.
A key unifying factor in his religion was to be an astronomical/astrological observatory built upon the pinnacle of a pyramid, or tower, at Babel. The building of this pyramid (or ziggurat) was interrupted by God himself in order to prevent Nimrod from extending his sway over all of the inhabited earth, according to Genesis.
God halted the work by confusing their language so they could no longer cooperate easily with one another, nor indeed easily inhabit the same region together. After their deaths, Nimrod and his wife Semiramis (the ancient "queen of heaven") were confirmed by their priests as gods and given homage as Marduk and Astarte.
There is one common element to Nimrod/Marduk in all his manifestations and that is the symbol of the snake/serpent/ dragon. From him spring various dragon myths and their special association with thunder and lightning and other apocalyptic events.
Nimrod took the dragon as his personal emblem. Strikingly the only favorable accounts of dragons are found among the Hamitic peoples of the world (like Nimrod) including the Ethiopians, Hittites, Chinese, Japanese and American Indian. The worship of Nimrod and Semiramis is the origin of all the pagan systems on earth.