The Raven Guard is one of the original First Founding Chapters of the Space Marines and was originally the XIXth Space Marine Legion before the Second Founding and the adoption of the Codex Astartes.
Named for a Terran avian seen by many Human cultures as the herald of fate and messenger of death, the Raven Guard have served the Emperor faithfully throughout the glories of the Unification Wars, the Great Crusade and the dark days of the Horus Heresy and beyond. From its earliest days, the warriors of the XIXth Legion were known as cunning and patient hunters, adept at biding their time until the moment to strike was at hand.
When the Legion was united with its primarch -- Corvus Corax, the Raven Lord, the Deliverer -- theirs was a form of warfare exemplifying speed, stealth and precision which was codified into their doctrine, and under the ivory-skinned, shadow-eyed and sable-haired primarch, the XIXth Legion carved its name in the annals of the Great Crusade.
As the tragic histories of the Horus Heresy were recounted, however, the Legion's glories were to be scattered upon the black sands of Isstvan V during the Drop Site Massacre, and the Imperium was almost shorn of one of its greatest champions. Though severely decimated, the Raven Guard would rise from the ashes of betrayal and go on to continue to serve the Imperium of Man as its protectors. As masters of the unseen war, they fight their battles with stealth and speed rather than fury and flames. For thousands of standard years, across thousands of worlds, they have continued to stalk the enemies of the Imperium as shadows of death, waiting for the perfect moment to deliver the killing blow before
melting back into the darkness once more.
The Raven Guard's Chapter homeworld is the planet called Deliverance, the airless mining moon of the Forge World Kiavahr, though its original name, before the Horus Heresy, was Lycaeus. The Raven Guard's fortress-monastery on Deliverance is known as the Ravenspire.
The Raven Guard are known for their cool-headed, even intellectual temperament, their superb infiltration skills and skill at furious, close-quarters engagements. The Raven Guard are the masters of unseen and guerrilla warfare, only engaging in frontal assaults when no other option presents itself.
The Raven Guard is also rightly feared for the potent Assault Marines and other close support units they field, who often prefer to wield a pair of Lightning Claws instead of the usual Bolt Pistol and chainsword. Kayvaan Shrike, the famed commander of the 3rd Company was the commanding officer of just such a unit before he ascended to the position of Chapter Master, known among the Raven Guard as the "Master of Shadows."