The Anunnaki - "Those who from heaven came" - are a group of deities in ancient Mesopotamian cultures. The Anunnaki appear in the Babylonian creation myth, Enuma Elish. In the late version magnifying Marduk, after the creation of mankind, Marduk divides the Anunnaki and assigns them to their proper stations, three hundred in heaven, three hundred on the earth.
Sumerian seal: Sumerian Inanna later Ishtar was the daughter of Ninurta. Besides the lions on her gate, her symbol is an eight-pointed palmettes and SIX-POINTED STAR. The LION was her symbol (detail of the Ishtar Gate). In the Babylonian pantheon, she "was the divine personification of the planet Venus
Nimrod probably did know the secrets. The Nephilum were still on the earth and there are various sources that state that he acquired the knowledge from two fallen angels. Those fallen angels were called Horus and Marduk. He also had incredible magical powers given to him by those fallen angels. Nimrod set himself up as superior to God in every conceivable way.