The Promethean Cult is a variation of the standard Imperial Cult that has been officially recognised by the Ecclesiarchy as a non-heretical faith that has deeply influenced the Salamanders Chapter of Space Marines and the people of their volcanic homeworld of Nocturne. The Promethean Cult calls on its followers to emulate the deeds and be true to the teachings of the Nocturnean Primarch Vulkan as well as providing service to and worship of his father, the Emperor of Mankind. Prometheans believe deeply in the virtues of self-reliance and self-sacrifice for others, long defining cultural values of the Nocturnean people, who have struggled to survive the harsh environment of their volcanic and earthquake-wracked homeworld. They hold a firm belief in isolationism. This is the tenet of their faith that only through spiritual meditation and exploration performed in isolation from others can a person gain a true understanding of both themselves and how they can best honour the legacy of Vulkan and serve the will of the Emperor. Prometheans make use of fire in many of their rituals and ceremonies and believe that they must be cleansed by the pain of fire before every major undertaking or initiative. The hammer, sometimes called Vulkan's Sigil, the forge and the anvil are also important symbols for Prometheans due to the importance of the art of smithing in Nocturnean culture.
Promethean believers also hold sacred the words of the ancient ritual book known as the Canticle of Immolation, which is often read by Salamanders Chaplains during the Chapter's various ceremonies. For the Salamanders Space Marines, Promethean beliefs manifest themselves most readily in the form of honour-scarring. Before and after every battle they engage in, a Salamander Astartes will have a symbolic scar burned into his body and another after the completion of combat, if he survives. Veteran Salamanders who have served the Chapter for hundreds of years and thousands of battles will have their entire body covered in honour-scars, including their ebon-skinned faces, which only receive the honour-scars after all the other skin on their body has already been so marked. As the Promethean Cult openly calls on its adherents to venerate the Primarchs and follow the Emperor loyally, it is not considered heretical by the Ecclesiarchy and instead has received official sanction as one of the accepted variants of the Imperium's state religion.
- Index Astartes IV, "Promethean Warriors - The Salamanders Space Marine Chapter"
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