The name means something to the effect of "those of royal blood" or "princely offspring", and has also been interpreted as "those who from heavan to earth came".
According to The Oxford Companion to World Mythology, the Anunnaki:
Their relation to the group of gods known as the Igigi is not always clear – at times the names are used synonymously, but in the Atra-Hasis flood 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.
When the Anunnaki appear in the Babylonian creation myth, Enuma Elish (the late version magnifying Marduk), after the creation of mankind, Marduk divides the Anunnaki and assigns them to their proper stations, in heaven and on the earth.
The Annunaki are mentioned in The Epic of Gilgamesh when Utnapishtim tells the story of the flood, which shares many similarities with Noah's deluge in the Bible.
In the Sumerian tale, the seven judges of the underworld are called the Annunaki, 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.
"There was a time, the Sumerians told, when civilized Man was not yet on Earth, when animals were only wild and undomesticated and crops were not yet cultivated. At that long ago time there arrived on Earth a group of fifty Anunnaki.
"Lead by a leader whose name was E.A. (meaning "Whose home is water ") they journeyed from their home planet NIBIRU and, reaching Earth, splashed down in the waters of the Persian Gulf... The time: 445,000 years ago. " (p.42)
The story, one of the oldest, if not the oldest in the world, concerns the birth of the gods and the creation of the universe and human beings. In the epic, Ea creates Lullu, the first man, to be a helper to the gods in their eternal task of maintaining order and keeping chaos at bay.
As the poem phrases it:
"Ea created mankind/On whom he imposed the service of the gods, and set the gods free."
Following this, Marduk "arranged the organization of the netherworld" and distributed the gods to their appointed stations. The poem ends with long praise of Marduk for his accomplishments.
It is said that one reason they came to earth in the first place was to obtain gold. A complex mining operation was begun which later, after revolts, required human hybrid slaves as labor.
Because their home planet Nibiru goes far out into space, these beings are in darkness and misery much of the time; when they approach the sun again they delight in visiting our planet Earth with the feminine essence of the Goddess so vibrant and living upon her.
There is evidence of these visits, including sexual encounters and hybrid offspring, throughout ancient history, particularly in the Sumerian culture.
It is written that when the Anunnaki visit our planet they interfere with its natural rhythms and nature. Being more technologically advanced with much longer lifespans, they were said to have genetically manipulated us in the distant past and considered us as their domesticated workers, or slaves, for their gold mines and to make their lives easier.
There is a part in Genesis of the Grail Kings, written by Laurence Gardner, which portrays the Anunnaki role in the history of mankind as parental and as teachers:
"The Sumerians 'believed’ that their main purpose in life was to serve the Anunnaki by providing them with food, drink, and habitation. In return, they were educated, trained in social skills, and academic affairs, and the products of this training are abundantly clear from their writings." (p. 102)