Innana is one of the earlist images of the Lady that survives into our present day, and she is Glorious. To the Sumerians she was both the Goddess of the Storm, and a Goddess of War, defending her people with her holy Lybris. So for her people she held the offices of Thor in the Norse Pantheon.
She was called Lady of Many offices, She was goddess of Fertility, and Goddess of Love. One prayer to her includes a verse where-in a young man asks Innana to bless him with a hot limbed wife, that she may bare him strong armed sons.
The tale of her decent into the underworld is the earliest such tale I am aware of to date:
Inanna makes her descent into the dark realm, kur- nu-gi-a, of her sister, Ereshkigal. Inanna passed the seven portals of kur-nu-gi-a, at each of the portals she was obliged to remove an item of clothing,until at last she stood before Ereshkigal, totally naked. Ereshkigal fastens on Inanna, and for three days she hangs like a carcass on a hook. Her faithful female companion, Ninshubur ("Queen of the East") whom she warns to go in search of help for her if she does not return, appeals to the god of wisdom, responds to her and sends two creatures to plead with Ershkigal for Inanna's release. They find Ereshkigal in the process of giving birth. Inanna is restored to life and ascends like the moon after its three days' death to assume her place once more as Queen of Heaven.
The lesson of this ritual drama for Sumerian culture was the deep realization that death is not inimical to life but an essential aspect of its totality and, indeed, the passageway to a new cycle of life. So her journey into the Netherworld was both a literal and symbolic enactment of a natural world occurrence and its mirror in the human psyche as represented by her earthly representatives: the priestesses of Sumeria.
A couple things I would like to mention if I may. Innana's story predates the myths of the Shepard King, including Jesus. It is her decent into the earth that makes the land grow barren, and her return that marks its rebirth. Easter with a Goddess! Yet the story also contains an aspect of Karmic Debt for Dummuzi must satisfy the debt to Ereshkigal, that Innana incurred by entering the underworld.
As a Tarot reader I see Innana's decent as the fools Journey, specifically that portion of the fools Journey where in we die. XIII of Trumps, and are brought into the underworld to confront our inner most darkness. XV Ereshkigal, Innana's sister and mirror, and have our ego's shattered by the experiance. The Tower, and the 7 Gates Through which Innana must pass surrendering the tokens of her Earthly Stations. Her Crown, Her Bangles, her Proud Garment. Before we face our Karmic Judgment we are stripped bare, here the Queen is no greater than the peasant girl. Yet having all her illustions laid bare, and her undergoing the "Ego Death" of the Tower. She is reborn in myth, or the soul having poured back into the river that which comes of the world, and now refined to a higher vibration Innana (the soul) is ready for her ascention into the sky to become the evening star.
Some people claim the Tarot goes back to Ancient Egypt, but we have no solid reason to believe that, what we can see however, is that the story, and the wisdom, encoded in the Trumps, is this story and it goes back to the beginning of human history. It is the key to understanding how a person can transcend the cycle of incarnation, and return to the divine source. It seems to me Innana is our first guide down that path.
If your interested I am including on the linked page a few thoughts about my relationship with Innana, and why she is important to me.