Ki (earth) in Sumerian mythology was the goddess and personification of the earth and underworld, chief consort of An (heaven) the sky god. Mesopotamian mythology is the collective name given to Sumerian Akkadian Assyrian and Babylonian mythologies from the land between the Tigris In Sumerian mythology and later for Assyrians and Babylonians Anu (also An; (from Sumerian *An = sky heaven was a sky-god In some legends Ki and An were brother and sister, being the offspring of Anshar ("Sky Pivot") and Kishar ("Earth Pivot"), earlier personifications of heaven and earth. In Akkadian mythology, Anshar (also spelled Anshur) which means "sky pivot" or "sky axle" is a Sky God. In the Akkadian epic Enuma Elish, Kishar is the daughter of Lahmu and Lahamu, the first children of Tiamat and Apsu
By her consort Anu, Ki gave birth to the Anunnaki, the most prominent of these deities being Enlil, god of the air. The Anunnaki (also transcribed as Anunnaku, Ananaki) are a group of Sumerian and Akkadian deities related to and in some cases Enlil ( EN = Lord + LIL = Loft "Lord of the Open" or "Lord of the Wind" was the name of a chief deity listed and written about in ancient Sumerian According to legends, heaven and earth were once inseparable until Enlil was born; Enlil cleaved heaven and earth in two. An carried away heaven. Ki, in company with Enlil, took the earth.
Some authorities question whether Ki was regarded as a deity. There is no evidence of a cult, and the name appears only in a limited number of Sumerian creation texts. This article discusses cult in the original and typically ancient sense of "religious practice" (cultus She later developed into the Babylonian and Akkadian goddess Antu, consort of the god Anu that had developed from the Sumerian An. In Akkadian mythology, Antu or Antum is a Babylonian goddess derived from the older Sumerian Ki, though the cosmogony has been altered to suit a separate In Sumerian mythology and later for Assyrians and Babylonians Anu (also An; (from Sumerian *An = sky heaven was a sky-god Samuel Noah Kramer identifies Ki with the Sumerian mother goddess Ninhursag, saying that they were originally the same figure. In Sumerian mythology, Ninhursag (NINURSAG was the earth and mother- Goddess, one of the seven great deities of Sumer.
Michael Jordan, Encyclopedia of Gods, Kyle Cathie Limited, 2002