Bull of Heaven in the context of "Epic of Gilgamesh"

Gilgamesh (/ˈɡɪlɡəmɛʃ/, /ɡɪlˈɡɑːmɛʃ/; Akkadian: 𒀭𒄑𒂆𒈦, romanized: Gilgāmeš; originally Sumerian: 𒀭𒄑𒉋𒂵𒎌, romanized: Bilgames) was a hero in ancient Mesopotamian mythology and the protagonist of the Epic of Gilgamesh, an epic poem written in Akkadian during the late 2nd millennium BC. He was possibly a historical king of the Sumerian city-state of Uruk, who was posthumously deified. His rule probably would have taken place sometime in the beginning of the Early Dynastic Period, c. 2900–2350 BC, though he became a major figure in Sumerian legend during the Third Dynasty of Ur (c. 2112 – c. 2004 BC).

Tales of Gilgamesh's legendary exploits are narrated in five surviving Sumerian poems. The earliest of these is likely "Gilgamesh, Enkidu, and the Netherworld", in which Gilgamesh comes to the aid of the goddess Inanna and drives away the creatures infesting her huluppu tree. She gives him two unknown objects, a mikku and a pikku, which he loses. After Enkidu's death, his shade tells Gilgamesh about the bleak conditions in the Underworld. The poem Gilgamesh and Aga describes Gilgamesh's revolt against his overlord Aga of Kish. Other Sumerian poems relate Gilgamesh's defeat of the giant Huwawa and the Bull of Heaven, while a fifth, poorly preserved poem relates the account of his death and funeral.

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.

The Epic of Gilgamesh (/ˈɡɪlɡəmɛʃ/) is an epic from ancient Mesopotamia. The literary history of Gilgamesh begins with five Sumerian poems about Gilgamesh (formerly read as Sumerian "Bilgames"), king of Uruk, some of which may date back to the Third Dynasty of Ur (c. 2100 BCE). These independent stories were later used as source material for a combined epic in Akkadian. The first surviving version of this combined epic, known as the "Old Babylonian" version, dates back to the 18th century BCE and is titled after its incipit, Shūtur eli sharrī ("Surpassing All Other Kings"). Only a few tablets of it have survived. The later Standard Babylonian version compiled by Sîn-lēqi-unninni dates to somewhere between the 13th to the 10th centuries BCE and bears the incipit Sha naqba īmuru ("He Who Saw the Deep(s)", lit. "He Who Sees the Unknown"). Approximately two-thirds of this longer, twelve-tablet version have been recovered. Some of the best copies were discovered in the library ruins of the 7th-century BCE Assyrian King Ashurbanipal.

The first part of the story discusses Gilgamesh, king of Uruk, and Enkidu, a wild man created by the gods to stop Gilgamesh from oppressing his people. After Enkidu becomes civilized through sexual initiation with Shamhat, he travels to Uruk, where he challenges Gilgamesh to a test of strength. Gilgamesh wins the contest; nonetheless, the two become friends. Together, they make a six-day journey to the legendary Cedar Forest, where they ultimately slay its Guardian, Humbaba, and cut down the sacred Cedar. The goddess Ishtar sends the Bull of Heaven to punish Gilgamesh for spurning her advances. Gilgamesh and Enkidu kill it, insulting Ishtar in the process. The gods decide to sentence Enkidu to death by giving him a fatal illness.