In Sumerian mythology, which god is the ruler of the underworld?

In Sumerian mythology, Ereshkigal is the ruler of the underworld.

Ereshkigal governs the realm of the dead, often called Kur or Irkalla in Mesopotamian traditions. Unlike Inanna, the goddess of love, fertility, and war, Ereshkigal is associated with death and the laws of the underworld.

The best-known story involving her is Inanna’s Descent to the Underworld. Inanna passes through seven gates, surrendering an item of clothing or regalia at each gate. Ereshkigal then condemns her, and Inanna’s return requires negotiation and substitution.

Ereshkigal is sometimes mistaken for a generic death goddess or for Inanna herself. They are separate sisters in the descent narrative. Ereshkigal’s role is sovereign and judicial: she controls the underworld’s boundaries, while other deities may enter only under specific conditions.