The story about Gilgamesh and his friend, Enkidu, was among the oldest literary works of mankind. According to legend, they fought each other and later became friends, fighting the Great Bull of Heaven; in that battle Enkidu was killed and mourned by his friend Gilgamesh. Their story was told by CaptainPicard to the dying TamarianDathon, whose species communicated through stories and tales. (TNG: "Darmok")
The story of Gilgamesh was related, according to the Star Trek Encyclopedia (4th ed., vol. 1, p. 306), through 12 incomplete stone tablets.
The story of Gilgamesh and Enkidu at Uruk is itself a metaphor for the situation of Picard and Dathon at El-Adrel: two people, initially combatants, come together to become friends and fight a common foe, a battle in which one of them is struck down and the other mourns his loss. (Mission Overview: Year Five, TNG Season 5 DVD special features)