He was the rebel son of Enki, the elder brother of Marduk, says the Sumerian story that Nergal was jealous of the popularity of his brother by the gods by defeating Tiamat, Nergal by envy his brother, trying to destroy him and the counsel of the Anunnaki gods but was prevented by Enki, who threw her son into the depths of hell, Negal became a ruthless demon who lived in the Sumerian desert, to cause destruction and death among gods and humans, is the only demon to live between two worlds on earth and in hell. Nergal was depicted as the chief of Hell's "secret police", and worked as "an honorary spy in the service of Beelzebub.
The Assyrian capital of Nineveh, but significantly, although Nebuchadnezzar II (606–586 BC), the great temple-builder of the neo-Babylonian monarchy, alludes to his operations at Meslam in Cuthah, 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.
In the late Babylonian astral-theological system Nergal is related to the planet Mars. As a fiery god of destruction and war, Nergal doubtless seemed an appropriate choice for the red planet, and he was equated by the Greeks to the war-god Ares (Latin Mars)—hence the current name of the planet.