The Epic of Gilgamesh is among the oldest surviving works of literature. It was originally a collection of five Sumerian poems, then later developed into a complete epic, with an initial, largely lost version dating back to the 18th century BCE, and a second, more complete rendering between the 13th and 10th centuries BCE. All versions center on the fictional Gilgamesh, king of Uruk, who was such a colossal jerk that the gods conspired to create a male companion to distract him, arguably making it a slash fic that predates the Bible.
The story begins with King Gilgamesh having a grand old time oppressing his constituents by humiliating the men in tests of strength and making excessive use of the droit du seigneur (‘right of the lord’), which allows him to sleep with women on their wedding night. His people cry out to the gods for help, and the gods answer with an unorthodox solution.
Anu, king of the gods, to the goddess Aruru:“go and createa double for Gilgamesh, his second self,
a man who equals his strength and courage,
a man who equals his stormy heart.
Create a new hero, let them balance each other
perfectly, so that Uruk has peace.”
And thus was born Enkidu, a wild man covered in hair, who wasted no time in making such a nuisance of himself by ruining hunting traps that Gilgamesh sent out a temple prostitute to spend a week ‘taming’ him. He may as well not have bothered, because the king soon had a prophetic dream, in which a meteorite fell at his feet.
Dearest child, this bright star from heaven,
this huge boulder that you could not lift –
it stands for a dear friend, a mighty hero.
You will take him in your arms, embrace and caress him
the way a man caresses his wife.
She also called this person ‘the companion of his heart’.
So begins the classic story of boy-meets-boy, boy-fights-boy-to-keep-him-from-raping-newlyweds, and boy-and-boy-make-up-and-bond-over-epic-monster-slaying-adventures.
All is well until the monster slaying gets out of hand (see the picture above in which our heroes slay the Bull of Heaven) and the two offend the goddess Ishtar, who was already upset by Gilgamesh refusing her advances. (A rational move on his part, given the ominous myths surrounding what happened to her other lovers.) Ishtar kills Enkidu, and Gilgamesh reacts the way one would expect when the love of their life was stolen from them.
Hear me, elders, hear me, young men,
my beloved friend is dead, he is dead,
my beloved brother is dead, I will mourn
as long as I breathe, I will sob for him
like a woman who has lost her only child.
[Etc.]But Enkidu did not answer. Gilgamesh
touched his heart, but it did not beat.
Then he veiled Enkidu’s face like a bride’s.
Later, he adds the rather graphic,
Six days and seven nights I mourned over him
and would not allow him to be buried
until a maggot fell out of his nose.
The second half of the Epic concerns Gilgamesh’s quest for immortality, so as to spare himself the fate that befell Enkidu. Along the way he encounters scorpion men (which he does not kill), lions (which he kills), and stone giants (which he regrets killing because they were the only living creatures who could cross the Waters of Death, but he solves the problem anyway by hitching a ride with a long-suffering ferryman). In the end, he fails to obtain immortality twice, and gives up.
Because it was written thousands of years ago and in a very different cultural context, it is impossible to determine whether the relationship between Gilgamesh and Enkidu would map better onto the modern concepts of bisexuality or bromance; but with the author very, very dead, readers are free to take whatever inspiration they like from the story. Sumer was certainly no stranger to people we now call queer, having developed a priest class for those assigned male at birth, who after joining were considered feminine.
The full text of the Epic can be found here, or in numerous other places online.