Ereshkigal in the context of "Kutha"

The ancient Mesopotamian underworld (known in Sumerian as Kur, Irkalla, Kukku, Arali, or Kigal, and in Akkadian as Erṣetu), was the lowermost part of the ancient near eastern cosmos, roughly parallel to the region known as Tartarus from early Greek cosmology. It was described as a dark, dreary cavern located deep below the ground, where inhabitants were believed to continue "a transpositional version of life on earth". The only food or drink was dry dust, but family members of the deceased would pour sacred mineral libations from the earth for them to drink. In the Sumerian underworld, it was initially believed that there was no final judgement of the deceased and the dead were neither punished nor rewarded for their deeds in life.

The ruler of the underworld was the goddess Ereshkigal, who lived in the palace Ganzir, sometimes used as a name for the underworld itself. Her husband was either Gugalanna, the "canal-inspector of Anu", or, especially in later stories, Nergal, the god of war. After the Akkadian Period (c. 2334–2154 BC), Nergal sometimes took over the role as ruler of the underworld. The seven gates of the underworld are guarded by a gatekeeper, who is named Neti in Sumerian. The god Namtar acts as Ereshkigal's sukkal, or divine attendant. The dying god Dumuzid spends half the year in the underworld, while, during the other half, his place is taken by his sister, the scribal goddess Geshtinanna, who records the names of the deceased. The underworld was also the abode of various demons, including the hideous child-devourer Lamashtu, the fearsome wind demon and protector god Pazuzu, and galla, who dragged mortals to the underworld.

The Sumerian word NIN (𒊩𒌆), later borrowed into Akkadian, was used to denote a queen or a priestess, and is often translated as "lady". Other translations include "queen", "mistress", "proprietress", and "lord". The word EREŠ, also meaning "queen" or "lady", is written using the cuneiform sign for NIN as well.

Many goddesses are called NIN or EREŠ, such as NIN.GAL ("great lady"), É.NIN.GAL ("lady of the great temple"), EREŠ.KI.GAL, and NIN.TI.

Nergal (Sumerian: 𒀭𒄊𒀕𒃲 KIŠ.UNU or GÌR.UNU.GAL; Hebrew: נֵרְגַל, Modern: Nerəgal, Tiberian: Nērəgal; Aramaic: ܢܸܪܓܲܠ; Latin: Nirgal) was a Mesopotamian god worshiped through all periods of Mesopotamian history, from Early Dynastic to Neo-Babylonian times, with a few attestations indicating that his cult survived into the period of Achaemenid domination. He was primarily associated with war, death, and disease, and has been described as the "god of inflicted death". He reigned over Kur, the Mesopotamian underworld, depending on the myth either on behalf of his parents Enlil and Ninlil, or in later periods as a result of his marriage with the goddess Ereshkigal. Originally either Mammitum, a goddess possibly connected to frost, or Laṣ, sometimes assumed to be a minor medicine goddess, were regarded as his wife, though other traditions existed, too.

His primary cult center was Kutha, located in the north of historical Babylonia. His main temple bore the ceremonial name E-Meslam and he was also known by the name Meslamtaea, "he who comes out of Meslam". Initially he was only worshiped in the north, with a notable exception being Girsu during the reign of Gudea of Lagash, but starting with the Ur III period he became a major deity in the south too. He remained prominent in both Babylonia and Assyria in later periods, and in the Neo-Babylonian state pantheon he was regarded as the third most important god, after Marduk and Nabu.

The Descent of Inanna into the Underworld (or, in its Akkadian version, Descent of Ishtar into the Underworld) or Angalta ("From the Great Sky") is a Sumerian myth that narrates the descent of the goddess Inanna (Ishtar in Akkadian) into the Underworld to overthrow its ruler, her sister Ereshkigal, the "Queen of the Dead." But following the removal of her adornments, she perishes and her corpse is suspended on a nail. The god Enki intervenes indirectly, restoring Inanna to life. However, on her return journey, Inanna is required to deliver another living human in exchange for her freedom. She selects Dumuzi, her spouse, who is abruptly transported to the Underworld. In response to the pleas of Dumuzi's sister, Geshtinanna, his circumstances are somewhat ameliorated: he is permitted to remain in the Underworld for only a portion of the year, with his sister assuming his role for the remaining duration.

The myth exists in two main versions: one in Sumerian and the other in Akkadian. The Akkadian version was first discovered and translated in the 1860s. The existence of the longer and older Sumerian version was first established in the early 20th century, but it required approximately fifty years for epigraphists to fully reconstruct and translate it.

In Sumerian religion, Gugalanna (𒄞𒃲𒀭𒈾 [GU₄.GAL.AN.NA] or 𒀭𒄘𒃲𒀭𒈾 [GU₂.GAL.AN.NA]) is the first husband of Ereshkigal, the queen of the underworld. His name probably originally meant "canal inspector of An" and he may be merely an alternative name for Ennugi. The son of Ereshkigal and Gugalanna is Ninazu. In Inanna's Descent into the Underworld, Inanna, the goddess of love, beauty, sex, and war, tells the gatekeeper Neti that she is descending to the Underworld to attend the funeral of "Gugalanna, the husband of my elder sister Ereshkigal". Some scholars consider Gugalanna to be the same figure as the Bull of Heaven, slain by Gilgamesh and Enkidu in the Epic of Gilgamesh.

Namtar (Sumerian: 𒉆𒋻, lit. 'fate') was a figure in ancient Mesopotamian religion who, depending on the context, could be regarded both as a minor god and as a demon of disease. He is best attested as the sukkal (attendant deity) of Ereshkigal, the goddess of the underworld. Like her, he was not the object of active worship, though references to it are made in literary texts, and additionally some incantations entrust him with keeping various other malevolent forces in the underworld.