The Black Legion is a fictional faction from the Warhammer 40,000 universe, known for its chaotic and malevolent nature. Originally part of the Loyalist Space Marines, they turned traitor during the Horus Heresy, aligning themselves with the dark powers of Chaos. The Black Legion is characterized by their black armor and their goal to spread chaos and destruction across the galaxy. Led by the powerful Abaddon the Despoiler, the Black Legion seeks to conquer and dominate, often clashing with the forces of the Imperium of Man. They are notorious for their brutal tactics and relentless pursuit of power, making them one of the most feared factions in the Warhammer 40,000 lore.