The Raven Guard were the XIX Legion of the original Space Marine Legions. Their Primarch is Corvus Corax . Their homeworld is Deliverance (originally named Lycaeus), a moon which orbits the Hive World Kiavahr. The Legion was devastated at the outbreak of the Horus Heresy and survived only by the most desperate of measures.
The Raven Guard specialise in guerrilla warfare, moving behind enemy lines with unrivalled stealth, and striking with precise application of force.