Enmerkar, according to the Sumerian king list, was the builder of Uruk, and was said to have reigned for "420 years" (or 900 as some copies). It adds that he brought the official kingship with him from the city of Eana, after his father Mesh-ki-ag-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", … Wikipedia
The definitive Wikipedia entry for Enmerkar. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/Enmerkar