Who is Tiamat from Myths from Mesopotamia: Creation, the Flood, Gilgamesh, and Others and what is their importance?

Tiamat is a sea goddess, who is personified as one of the primeval gods of creation. She is "chaos", she is also the wife of Apsu. With her husband, Tiamat creates the first generation of Gods, but she is unhappy when they kill her husband, who in turn, had planned to kill his children. Tiamat and her lover then wage war against Marduk and his army. She is slaughtered, and her body is used to create the Earth.