The Salamanders are one of the Loyalist First Founding Chapters of Space Marines.
They originally served as the Imperium's XVIII Space Marine Legion during the Great Crusade and the Horus Heresy and for some time before the return of their Primarch were known as the "Dragon Warriors." Their homeworld is the volcanic Death World of Nocturne.
The Salamanders as a Chapter are unusually concerned with civilian casualties compared to most other Space Marines and believe that one of their most important duties is to protect the lives of the Emperor of Mankind's innocent subjects whenever and wherever possible.
This is an attitude that developed as a consequence of the Salamanders' own unusually close connections to the Nocturnean people, as they are one of the only Chapters of Astartes who continue to interact with their families and the people of their homeworld after their transformation into Space Marines.
For instance, it is not uncommon for a Salamander to serve as a clan leader among the Nocturneans and live with them when Chapter business does not require him to remain at the Chapter's fortress-monastery on Nocturne's moon of Prometheus.
The Salamanders and their people as a whole are also defined by their adherence to a variation of the Imperial Cult called the Promethean Cult.
The story of the Salamanders and the legend of how their Primarch Vulkan was reunited with the Emperor is one of the few stories from the time of the Great Crusade told in a coherent form across many different worlds of the Imperium.
How much of the so-called Promethean Opus is factually accurate is unknown, and in many ways unimportant.
The fact that the Salamanders have stood for ten thousand standard years as paragons of strength, honour and resolution is the true legacy of their Primarch, and one that endures into the dark epoch of the late 41 Millennium.
The Salamanders hail from a world wracked by constant volcanic instability, but possessing the very rarest kinds of mineral resources.
The violence of the cyclic volcanic activity creates and churns up minerals highly prized by the Adeptus Mechanicus, yet the planet has been occupied by Mankind since long before the Age of the Imperium.
When the infant Vulkan appeared on Nocturne, he was discovered by the smith of one of the seven main settlements, a mastercraftsman who soon taught the infant Primarch all he knew.