Enmerkar from Wikipedia
Enmerkar, according to the Sumerian king list, was the builder of Uruk in Sumer, and was said to have reigned for "420 years" (some copies read "900 years").
The king list adds that Enmerkar brought the official kingship with him from the city of E-ana after his father Mesh-ki-ang-gasher, son of Utu, had "entered the sea and disappeared."
Enmerkar is also known from a few other Sumerian legends, most notably Enmerkar and the Lord of Aratta, where a previous confusion of the languages of mankind is mentioned. In this account, it is Enmerkar himself who is called 'the son of Utu' (the Sumerian sun god). Aside from founding Uruk, Enmerkar is said here to have had a temple built at Eridu, and is even credited with the invention of writing on clay tablets, for the purpose of threatening Aratta into submission. Enmerkar furthermore seeks to restore the disrupted linguistic unity of the inhabited regions around Uruk, listed as Shubur, Hamazi, Sumer, Uri-ki (the region around Akkad), and the Martu land.
Three other texts in the same series describe Enmerkar's reign. In Enmerkar and En-suhgir-ana, while describing Enmerkar's continued diplomatic rivalries with Aratta, there is an allusion to Hamazi having been vanquished. In Lugalbanda and the Mountain Cave, Enmerkar is seen leading a campaign against Aratta. The fourth and last tablet, Lugalbanda and the Anzud bird, describes Enmerkar's year-long siege of Aratta. It also mentions that fifty years into Enmerkar's reign, the Martu people had arisen in all of Sumer and Akkad, necessitating the building of a wall in the desert to protect Uruk.
In these last two tablets, the character of Lugalbanda is introduced as one of Enmerkar's war chiefs. According to the Sumerian king list, it was this Lugalbanda "the shepherd" who eventually succeeded Enmerkar to the throne of Uruk. Lugalbanda is also named as the father of Gilgamesh, a later king of Uruk, in both Sumerian and Akkadian versions of the Epic of Gilgamesh.
David Rohl has claimed parallels between Enmerkar, builder of Uruk, and Nimrod, ruler of biblical Erech (Uruk) and architect of the Tower of Babel in extra-biblical legends. One parallel Rohl noted is the description "Nimrod the Hunter", and the -kar in Enmerkar also meaning "hunter". Rohl has also suggested that Eridu near Ur is the original site of Babel, and that the incomplete ziggurat found there - by far the oldest and largest of its kind - is none other than the remnants of the Biblical tower.
In a legend related by Aelian  (ca. AD 200), the king of Babylon, Euechoros or Seuechoros (also appearing in many variants as Sevekhoros, earlier Sacchoras, etc.), is said to be the grandfather of Gilgamos, who later becomes king of Babylon (i.e., Gilgamesh of Uruk). Several recent scholars have suggested that this "Seuechoros" or "Euechoros" is moreover to be identified with Enmerkar of Uruk, as well as the Euechous named by Berossus as being the first king of Chaldea and Assyria. This last name Euechous (also appearing as Evechius, and in many other variants) has long been identified with Nimrod.