Warhammer 40k Lore: Where to Start -- The Emperor
The Emperor of Mankind is the leader of the Imperium, but he's more than a leader: he is a father and a god to them. He created the Space Marines, created the Primarchs, and it is through his incredibly psychic abilities that the Imperium continues to exist as well as allows Imperium ships to travel through the Warp.
Let's dig a little deeper into the Warhammer 40k's Emperor and see where he began, how he grew in strength, what he accomplished, and what has brought him to his terrible state: a corpse of a man secured in The Golden Throne, barely alive (if he can be said to be alive at all).
The Origins of The Man Who Would Be Emperor
Admittedly, the origins of the Emperor are not entirely known, and different books of the Black Library--and especially the very early versions of Rogue Trader and Warhammer 40k--give differing accounts of his life.
The Emperor was born on Earth around 8,000 BC in a Hittite village. Although naturally born of a woman, he was the product of a group of powerful psykers known as Shamans, who joined together to give all of their power into one individual--a being who would be more powerful than all of them and would be able to stop the evils of Chaos.
As a man, the Emperor was a king with strong psychic abilities who understood intuitively his role to be the protector and defender of humanity. However, as he was seeking to unite the mankind (through warfare) he was betrayed and stabbed.
However, the Emperor was immortal, and continued to live, in secret and in shadow, for millennia.
This is where things get interesting: the Emperor entered the Gateway into the realm of Chaos and there met with the Dark Gods, who bestowed their power upon him in exchange for the Emperor spreading Chaos into humanity. The Emperor went back on the deal, though, betraying Chaos (making an eternal enemy) and using his newfound power to create the Primarchs.
The Webway and the Warp
At this point he also made it his primary purpose to create the Webway. The Webway is an alternate method of faster-than-light travel, different from using the Warp. (The Warp is also known as the Immaterium, as well as the Realm of Chaos. It is a psychic dimension through which it is possible to travel between worlds. The Warp, or Immaterium, is to the Material World, as a stream is to the shore: someone can jump from the stationary shore, enter the stream and travel much faster, though caught up in extremely treacherous conditions.)
The Emperor needed to reunite all mankind, from all around the galaxy, and he knew that the Webway would be the safest route to do that, and would prevent Chaos from affecting mankind.
Becoming the Emperor and the Great Crusade
After a period called The Age of Strife, the Emperor--who had been a warlord and king--was officially the Emperor of Terra. He began making the proper preparations to allow him to reach out through the galaxy and reunite all of humanity's colonies.
Two of the main things that he needed was to create, first, the Astronomicon, a massively powerful beacon that used the Emperor's psychic abilities, and second, the Primarchs, twenty children based on his own genes. (The Emperor referred to them as his sons.)
Unfortunately, things went wrong, and while accounts differ as to what happened, the Primarchs were cast into the Warp and thought to be lost. The Emperor's own psychic abilities told him the children were alive.
This was when the Emperor created the Space Marines, twenty legions each from the genetic material of a Primarch. Originally, the Space Marines gene-seed was unstable and the soldiers didn't last long. But still, they were sent on the Great Crusade.
The Great Crusade began with rejoining the Mechanicum of Mars in peace (the Mechanicum would eventually be the driving force for all technological knowledge of the Imperium), and driving Xenos from Saturn and Jupiter, retaking the Sol System in its entirety.
Then the Emperor led the Space Marines out into the galaxy, unifying the human worlds and, most importantly, finding the twenty Primarchs. The first Primarch, both first to be created and first to be found, was Horus. Horus and the Emperor fought side-by-side through many battles for many years, but, in an important turn of events, the Emperor left the Space Marines and returned to Terra to return to his work on the Webway Project.
The Horus Heresy
The Emperor kept his project secret from the Primarchs, including Horus (who had been named as Warmaster). Horus and many of his brethren felt that this was a betrayal of the Great Crusade, an abandonment of the Emperor's duties. It also, to them, showed a lack of trust and respect.
The other big problem was that the Emperor formed the Council of Terra, an administrative body that led the Imperium's day-to-day issues--but the Primarchs were excluded from this Council.
Finally, Horus was wounded in battle with a weapon that had been cursed by Nurgle, one of the Chaos gods. The wound would not heal. While the priests attempted to heal him, Horus saw in a a vision (through the Warp) the future of the Imperium as a totalitarian and oppressive regime in which the Emperor was worshipped as a god. (All of this came true, of course, but Horus was made to see Chaos as the victims.)
Horus changed loyalty and joined Chaos, and was successful in swaying half of the twenty Primarchs to join him. This created a galaxy-wide civil war. One of the Primarchs, Magnus, tried to warn the Emperor telepathically of the coming war, but in the process damaged the Webway Project (the Golden Throne) and enraged the Emperor who banished Magnus.
Because of the Webway breach, Chaos demons were able to flood Terra. Two groups of the Emperor's closest and most elite soldiers, the Adeptus Custodes and the Sisters of Silence, held off the demons while the Emperor worked desperately to save Terra.
The Siege of Terra
The Siege of Terra was the final campaign that would determine the fate of the Horus Heresy and of Horus himself. The legions of Chaos attacked Terra and the Palace of the Emperor.
Magnus, Primarch of the Thousand Sons, who had been banished by the Emperor and believed he was betrayed, breached the inner part of the Palace to kill the Emperor. The Emperor offered Magnus a chance to be redeemed, and showed Magnus a vision of a future where the Primarchs were reunited and all the galaxy was taken by mankind. However, the Thousand Sons were cursed because of their part in the siege, and could not be redeemed. Magnus therefore refused and tried to kill the Emperor, but was stopped by Vulkan, the Primarch of the Salamanders.
The Emperor ordered that a thousand psykers be sacrificed, the cost of running the Golden Throne while the Emperor was away for a single day, and the Emperor sought out Horus on his ship, the Vengeful Spirit. Upon arrival he found that Horus had just killed Sanguinius, the Primarch of the Blood Angels, and the Emperor declared that Chaos had taken power over Horus, not the other way around.
Using a blast of his full psychic energy, the Emperor pierced through the heart of Horus. In a final moment of clarity, Horus realized what he had done and begged to be destroyed before Chaos could take his body. The Emperor agreed and destroyed his son.
However, the act nearly killed the Emperor and all he could do was ask Rogal Dorn, Primarch of the Imperial Fists, to take him back to the Golden Throne.
The Golden Throne
And that is where the Emperor's body has remained for the last ten thousand years: encased in the Golden Throne. He is kept alive by biomachinery. He appears physically to be nothing but a corpse, but his will lives on.
It is through his undying power that the Astronomicon continues to work allowing Imperium ships to navigate the Warp. He also appears to some humans in dreams and visions, giving guidance and counsel.
The Golden Throne also stops the broken Webway from allowing Chaos back onto Terra.
In one of the only known instances of face-to-face communication with the Emperor, Robute Guilliman, Primarch of the Ultramarines, talked with his father but sensed coldness and distance.
The Future of the Emperor
There are two theories about the future of the Emperor: the Star Child, and the Sensei Emperor.
The Star Child theory posits that the Emperor had children while a man, and that the Emperor's soul is currently living in the Warp creating a new soul. One of these children of the Emperor will one day become one with this new soul and become the Star Child--but that cannot happen while the Emperor still lives on his Golden Throne.
The second theory, the Sensei Emperor, says that a group called the Illuminati believe that the death of the Emperor will bring about a fifth god of Chaos and create another Eye of Terror (a rift where the Warp and real space mix) which would span the entire galaxy. In order to stop this they want to gather all of the Emperor's chldren (known as Sensei) and sacrifice them all at once which will renew the Emperor, now the Sensei Emperor, to once again lead as a fully-healed human.
What do you think of the Emperor of Makind? Is he a hero or a villain? What will become of him and his Golden Throne?