The Epic of Gilgamesh is contained on twelve large writings, and since the original discovery, it has been found on others, as well as having been translated into other early languages.
The actual writings date back to around 650 B.C. and are obviously not originals since fragments of the flood story have been found on tablets dated around 2,000 B.C.8 Linguistic experts believe that the story was composed well before 2,000 B.C. compiled from material that was much older than that date.
The Sumerian cuneiform writing has been estimated to go as far back as 3,300 B.C.
The Epic was composed in the form of a poem. The main figure is Gilgamesh, who actually may have been an historical person.
The Sumerian KingList shows Gilgamesh in the first dynasty of Uruk reigning for 126 years. This length of time is not a problem when compared with the age of the pre-flood patriarchs of the Bible. Indeed, after Gilgamesh, the kings lived a normal life span as compared with today.
The King List is also of interest as it mentions the flood specifically
"the deluge overthrew the land."