The Annunaki were the main gods of the Sumerian pantheon. Their name and certain aspects of their mythology have been co-opted by certain theorists on several occasions.
The name is variously written “a-nuna”, “a-nuna-ke-ne”, or “a-nun-na”, meaning “princely offspring” or “offspring of Anu”. Alternative translations of the name, such as “those who from the heavens came to earth”, based on the work of Zecharia Sitchin have been rejected by scientists and academics, who dismiss his work as pseudo-scientific.
According to The Oxford Companion to World Mythology, the Anunnaki: “…are the Sumerian deities of the old primordial line; they are chthonic deities of fertility, associated eventually with the underworld, where they became judges. They take their name from the old sky god An (Anu).”
Their relation to the group of gods known as the Igigi is unclear – at times the names are used synonymously but in the Atra-Hasisflood myth the Igigi are the sixth generation of the gods who have to work for the Anunnaki, rebelling after 40 days and replaced by the creation of humans.
Jeremy Black and Anthony Green offer a slightly different perspective on the Igigi and the Anunnaki, writing that “lgigu or Igigi is a term introduced in the Old Babylonian Period as a name for the (ten) “great gods”. While it sometimes kept that sense in later periods, from Middle Assyrian and Babylonian times on it is generally used to refer to the gods of heaven collectively, just as the term Anunnakku (Anuna) was later used to refer to the gods of the underworld. In the Epic of Creation, it is said that there are 300 lgigu of heaven.”
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. In gratitude, the Anunnaki, the “Great Gods”, built Esagila, the splendid: “They raised high the head of Esagila equaling Apsu. Having built a stage-tower as high as Apsu, they set up in it an abode for Marduk, Enlil, Ea.” Then they built their own shrines.
The Anunnaki are mentioned in The Epic of Gilgamesh when Utnapishtim tells the story of the flood. The seven judges of hell are called the Anunnaki, and they set the land aflame as the storm is approaching.
According to later Assyrian and Babylonian myth, the Anunnaki were the children of Anu and Ki, brother and sister gods, themselves the children of Anshar and Kishar (Skypivot and Earthpivot, the Celestial poles), who in turn were the children of Lahamu and Lahmu (“the muddy ones”), names given to the gatekeepers of the Abzu (House of Far Waters) temple at Eridu, the site at which the creation was thought to have occurred. Finally, Lahamu and Lahmu were the children of Tiamat (Goddess of the Ocean) and Abzu (God of Fresh Water).