Horus

Horus was one of the twenty Primarchs of the Imperium of Man in the Warhammer 40,000 universe.

Chaos stole the fetal Primarchs from their laboratory and scattered them across the cosmos, but after many years of searching, the Emperor recovered them and gave them leadership of the Space Marine legions based on their genetic material. Horus was given command of the Luna Wolves, who were later renamed "Sons of Horus," and Horus himself was bestowed with the title Warmaster.

During a mission on the planet Davin, Horus was wounded, and required downtime to heal. During his downtime, he was inducted into a "warrior lodge." Although the ceremony was intended to make him a "brother" rather than an outsider, the lodge was rife with Chaos taint, and it affected Horus greatly. He introduced the ideal to the Chapters under his direct command, and then it spread to half of the Legions. Horus also introduced the concept of desposing the Emperor and installing himself, a strong leader willing to take the fight to the enemies of Mankind.

The Emperor sent Horus to Istvaan III to suppress a rebellion. Horus dropped a bioweapon into the atmosphere, which killed the 12 billion inhabitants in seconds; the psychic shockwave was said to be louder than the Astronomican.

Nine Space Marine Chapters declared their allegiance to Horus, and the remaining nine fought them across the Empire in the horrific Horus Heresy. As the civil war drew to a close, the Traitor Legions beat at the defences of Holy Terra.

Horus ordered the deflector shields of his flagship dropped, so the Emperor and his bodyguards could teleport onto the ship, possibly out of some vestige of honour that remained in Horus's body. Sanguinius, Primarch of the Blood Angels, appeared before him, and Horus offered him riches and power if he denounced his allegiance to the "false" Emperor. Sanguinius refused and attacked. Horus quickly killed him, and was still standing over his broken body when the Emperor entered the chamber.

The Emperor fought Horus, power sword against lightning claw, with brutal blows that would eviscerate any mortal man dozens of times over. The Emperor held back for much of the battle, remembering Horus as his beloved son and not wishing to believe that he had turned so utterly to Chaos. This allowed Horus to inflict crippling mortal wounds on the Emperor, since nothing short of the Emperor's full power would be sufficient to defeat him. At the critical point in the battle, a lone Space Marine in Terminator armour, probably of the Blood Angels Legion, entered the room: Horus flayed him alive with but a look, and in that instant the Emperor realised how far his favoured son had turned. With iron resolve this time, he gathered his full strength and delivered a massive psychic blow that killed Horus almost instantly. In his final moments, the powers of Chaos were driven from him, and the Emperor sensed his favoured son's return to sanity for a fraction of a second before he was annihilated.

After the battle, Rogal Dorn, Primarch of the Imperial Fists entered the chamber to find the Emperor mortally wounded, and brought him back down to Terra where the Golden Throne, a giant life-support machine, was constructed to keep the Emperor alive, where he remains to this day.

Abaddon the Despoiler, the current Chapter Master of the Black Legion (formerly Sons of Horus, formerly Luna Wolves), found Horus's body after Rogal Dorn left the ship with the bodies of Sanguinius and the Emperor. He took Horus' right-hand lightning claw, the Talon of Horus, as his own.