Abridged History of the Nether

In the beginning, the Nether was the hot center of the world. The nether did not have Bottom-Rock {Bedrock} on top of it separating it from the Overworld. The Essence payed no attention to the Nether, for it was a horrible inhospitable place. What he did not know was that some tunnels connected to the Nether, and that all the evil was spewing over and changing the Overworld.
What some people don't know is that Pigmen were not created in the Nether by Nether-Men, but it was actually made many millions of years before. It was - of course - the preceding step to Pigmen, so it was not the same as to what people consider Pigmen to be.

These Pigmen were quasi-sentient, their cranium proves this. They had long tusks sprouting from the bottom of their jaws, they seem to have crouched when walking and slaughter whatever was in sight.
The Essence felt them and destroyed them. He looked for the source of their existence and discovered the putrefied old tunnels under the world. He chose to separate these two worlds by and almost indestructible object: Bedrock. s if this was not enough, he hid the Nether in a large gaseous substance known as the Void.
It was so that the Nether was separated from the world and that it has evolved independently from the Overworld.

By: Loreguy