Mesopotamian god of the atmosphere, in many senses the most important god in the pantheon, if not the highest. His importance must be ascribed to his being the god of nature's cycles and fertility.
Enlil was the son of the highest god Anu. His main cult centre was at Nippur in today's Iraq. The meaning of "Enlil" is best translated into "Lord of the Wind," or "Lord of the Air."
IN SUMERIAN RELIGION

In Sumerian religion, Enlil was the god of both the atmosphere and the wind. In many respects he is the most active god in the Sumerian pantheon.
He is called "father of gods," "king of heaven and earth" and "king of all lands." In the myths, Enlil is presented as the one who separated heaven and earth, the one who lets everything grow, who created agricultural tools, who created the day and who decided upon the destiny of the world. But Enlil is also the god of storms and bad weather.
In one myth we hear about Enlil raping Ninlil, the grain goddess, whereupon he was banished to the underworld, in order to return to the world, reflecting the cycles of agriculture.
Moreover, Enlil is the god who gave kings their positions, and who gave them progress in war and in peace.
IN ASSYRIAN / BABYLONIAN RELIGION

In Babylonian and Sumerian religion, Enlil upholds his Sumerian name, and he is often called "king of earth" and as with, Anu he was called, "father of gods" or "king of gods."
Enlil is a strong, powerful and merciless god, who could be represented by the storm flood or the hurricane. He is the god who sent the Cataclysm to the earth. He once even created the monster Labbu in order to wipe out all humankind.
IN AKKADIAN RELIGION

The qualities of Enlil in Akkadian religion resembled those in Sumerian and Babylonian religions. But his name had changed to Bel, "the Lord," which has the same root as with the god, Baal, of West Semitic religions. And he had also developed into becoming the god of order and destiny.