The importance of Kutha as a religious and at one time also as a political centre led to his surviving the tendency to concentrate the various sun-cults of Babylonia in Shamash. He becomes, however, the representative of a certain phase only of the sun and not of the sun as a whole. Portrayed in hymns and myths as a god of war and pestilence, Nergal definitely seems to represent the sun of noontime and of the summer solstice which brings destruction to mankind. It follows logically that Nergal becomes the deity who presides over the nether-world, and who stands at the head of the special pantheon assigned to the government of the dead (supposed to be gathered in a large subterranean cave known as Aralu or Irkalla). In this capacity he has associated with him a goddess Allatu, though at one time Allatu may have functioned as the sole mistress of Aralu, ruling in her own person. Ordinarily Nergal pairs with his consort Laz. Standard iconography pictured Nergal as a lion, and boundary-stone monuments symbolise him with a mace surmounted by the head of a lion.
As in the case of Ninib, Nergal appears to have absorbed a number of minor solar deities, which might account for the various names or designations under which he appears, such as Lugalgira, Sharrapu ("the burner," perhaps a mere epithet), Ira, Gibil (though this name more properly belongs to Nusku), and Sibitti. A certain confusion exists in cuneiform literature between Ninib and Nergal, perhaps due to the traces of two different conceptions regarding these two solar deities. Nergal has epithets such as the "raging king," the "furious one," and the like. A a play upon his name - separated into three elements as Ne-uru-gal (lord of the great dwelling) - expresses his position at the head of the nether-world pantheon.
In the astral-theological system Nergal becomes the planet Mars, while in ecclesiastical art the great lion-headed colossi serving as guardians to the temples and palaces seem to symbolise Nergal, just as the bull-headed colossi probably typify Ninib.
Nergal's chief temple at Kutha bore the name E-shid-lam, from which the god receives the designation of Shidlamtaea, "the one that rises up from Shidlam."
The cult of Nergal does not appear to have spread as widely as that of Ninib. Hymns and votive and other inscriptions of Babylonian and Assyrian rulers frequently invoke him, but we do not learn of many temples to him outside of Kutha. Sennacherib speaks of one at Tarbisu to the north of Nineveh, but significantly, although Nebuchadnezzar II (606 - 586 BC), the great temple-builder of the neo-Babylonian monarchy, alludes to his operations at E-shid-lam in Kutha, he makes no mention of a sanctuary to Nergal in Babylon. Local associations with his original seat - Kutha - and the conception formed of him as a god of the dead acted in making him feared rather than actively worshipped.
Text originally from the 1911 Encyclopedia Britannica.