According to available historical records, the king of Uruk in Babylon is known as Gilgamesh. He is a known historical figure and ruled around 2700 BC from a place which is now part of Iraq. The civilization which prospered between the two rivers, the Tigris and the Euphrates, were among the very first to trigger growth of civilizations elsewhere in the west and the east.
Mesopotamia Gilgamesh was the subject of several stories and myths recorded around 2000 BC in the predominant Sumerian language of the time. Archaeologists have unearthed clay tablets on which scripts were written in Sumerian eulogizing the great King Gilgamesh. Studies have revealed that the language bears no resemblance to any modern language and was unique in ancient Mesopotamia.
Epic from 7 BC:
Stories and poems about Gilgamesh were also written in Akkadian which was a Semitic version of the prevailing Sumerian tongue spoken by common people. Akkadian was the favorite language for official purposes and was also preferred for literary pursuits as well. Our knowledge about Gilgamesh has come from the various writings and epic poems penned during the period in ancient Mesopotamia.
It is also one of the earliest known literary works of the world which also helped shape literary pursuits elsewhere once civilizations started prospering. Scholars on ancient Mesopotamian culture believe that the epic on Gilgamesh was initially written in Sumerian and at a later period, adapted as a longer version in Akkadian as well.
If you are looking for the complete version, you will have to rely on the surviving 12 tablets from the time of King Ashurbanipal of Assyria dating back to 7 BC.
The epic was centered on Gilgamesh and a wild man, Enkidu, who was his companion. They had gone on a hairy trail to the Cedar Mountain by defying the gods in a bid to finish off the monster Humbaba.
After accomplishing their task and infuriating the gods, Gilgamesh and his companion went on to kill the Bull of Heaven sent by Ishtar, the goddess whose advances they spurned. Mesopotamia Gilgamesh is a popular story and has been translated in several languages.