The earliest known poems about Gilgamesh were composed in Sumerian.
These early poems are separate Sumerian compositions about the king of Uruk, including stories about Gilgamesh and Huwawa, Gilgamesh and the Bull of Heaven, and Gilgamesh’s conflict with Aga. They were written centuries before the better-known Standard Babylonian Epic of Gilgamesh was compiled.
The Standard Babylonian version is written in Akkadian, a Semitic language, and combines older material into a connected literary narrative. This distinction explains why both Sumerian and Akkadian are associated with Gilgamesh, but they refer to different stages of the tradition.
The surviving evidence comes from clay tablets written in cuneiform. Because the manuscripts were copied over long periods and many are fragmentary, scholars reconstruct the history of the poem from multiple versions rather than from one original manuscript.