Et'Ada

Et'Ada, also called the "Original Spirits", are the things perceived and revered by the mortals as gods or spirits. To humans these Et'Ada are the Gods and Demons. To the Aldmer, the [] ([]i translation is "our ancestors") and [] (Aldmeri translation is "not our ancestors"). The Aedra and Daedra came to be once [] convinced/tricked the Original Spirits (Et'Ada) to create []. The Daedra are the descendant spirits of the Et'Ada who left during the creation of Mundus to retain their power. The Aedra are the descendant spirits of the Et'Ada who remained during the creation of Mundus, thus giving away a significant amount of their power.

Theories
According to the book Sithis, Anu isn't a deity of any kind, but is rather a static force without consciousness, personality, intent or will, being immutable static light. Something cannot be created without changing the creator, and Anu is static, and does not change.

It is Sithis, according to this book, that created all things. Sithis sundered the Eternal Anu to create new ideas. Unfortunately, some of these ideas became manifest and desired to be as eternal as Anu.

This created Aedra and the Aedra. Sithis then created Lorkhan to destroy these false creations.