The Man In The Golden Throne

The Imperium of Man spans the entire Milky Way galaxy. The estimated total number of Imperial citizens are in the hundreds of trillions. Many more are expected to be living in colonies on worlds long forgotten, waiting to be rediscovered since the Age of Darkness. The High Lords of the Imperium have controlled this vast galactic realm for more than ten millennia in the name of the Emperor.

During the time of the Great Crusade, the Emperor himself led Imperial Forces to countless worlds previously lost during the Age of Darkness and brought back into the fold of the Imperium. The Golden Age of Mankind soon followed but this was cut short when traitorous Space Marine legions rebelled against the Emperor during the Horus Heresy. It took no less than the Emperor himself to end this civil war when he slew the leader of the rebellious forces who was also his friend before the uprising, in the epic Battle of Terra. Although he was victorious, the Emperor's body was devastated and he kept himself alive only through sheer force of will.

Today the  Emperor lies in the Golden Throne, a miraculous construction by the Adeptus Mechanicus that now sustains his shattered physical form and allows his great mind to soar in the warp. He is the beacon that guides ship navigators through the perilous journey through warp space and without him, warp travel would be nigh impossible. But he is also the guiding light that binds the Imperium together, for he is its founder, its savior, its god.

But long before the Imperium was established, the immortal Emperor had already walked among men. He kept a personal journal whose existence is known only to and is now under the care of the Adeptus Custodes, the Eternal Guardians of the Golden Throne. The journal dates back to the time when he had not yet risen to prominence and was known to his fellows as an ordinary man. For reasons known only to himself, he traveled from Terra to the new worlds during the early age of warp travel. He would stay for a short period of time on one world before departing for another. His journeys took him to thousands of colonized planets and lasted until just before the collapse of the ancient central government on Terra.

Before his return to Terra, the Emperor had resided on the small agri-world of San Leor, near the southeastern fringe of the galaxy. But unlike all the other worlds he had visited, it is here that he would leave his greatest legacy. Although his reasons remain a divine mystery to this day, he married a local woman and they had a daughter. They lived as an ordinary family until his wife died unfortunately from a mysterious illness, a year after their only child was born. 

When news of the events from Terra reached San Leor, the Emperor knew that mankind would fall into anarchy and was doomed extinction without a strong force to unite them. At long last, the time had come for him to set his plans into motion. But for her own safety, he also knew he could not take his daughter with him. So the next day and with a heavy heart, the Emperor entrusted the care of his only child to a couple whom he had befriended when he first arrived on the planet. Soon afterwards, he left San Leor to build the Imperium that we know today.

What little else is known about the fate of the Emperor's daughter comes from the Emperor himself. Although he could not be with her in flesh, he was always with her in spirit. His powers allowed him watch over her despite the enormous distance between them. But he also knew that he would never see her again. 

Legends say that before the Emperor left the Imperial Palace to face Horus, he told Rogal Dorn that there was only one thought that saddened him more than the treachery of the Warmaster. When the Imperial Fist Primarch asked what it was, the Emperor remained silent.