The Death Guard, originally known as the Dusk Raiders, were the XIV Legion of the Legiones Astartes. Their Primarch, Mortarion, grew up on the toxic world of Barbarus, where he learned to survive amid poisonous mists and death. This resilience became the Legion’s core – tough, stoic, and unyielding.

During the Horus Heresy, the Death Guard became a key force among the Traitors. On Isstvan III and V, they were an unstoppable bulwark that broke the Loyalist lines. After the betrayal, Mortarion and his Legion fell fully under the sway of Nurgle, the God of Decay. Their bodies became living hives of disease yet immune to pain and fear.

In the Horus Heresy game system, the Death Guard possess rules such as Remorseless, allowing them to move without penalties and fire as if stationary. Their forces include Grave Wardens, Deathshroud Terminators, Plague Marines, and heroes like Calas Typhon and Ignatius Grulgor.