The planet Mars has changed enormously since man first set foot upon its barren and arid surface. In the early 22nd century it became the first world to be terraformed. It was given an atmosphere and its deserts were turned into fertile soil. However, agriculture is and was never very important on Mars - its main source of wealth lay below its surface in the form of gems, minerals and metal ores.

Once terraformed, Mars was settled by industrial cartels and their workforces, and soon grew into the first human hive world. Mars became a centre for industrial production and research, and its very name has become synonymous with technical expertise and scientific advancement. Mars became the hub for further space exploration throughout the solar system.

Today Mars has evolved into the workshop of the Adeptus. Its factory hives produce the bulk of all technical equipment used in the Imperium. Spacecraft and other large specialised constructs are fabricated in the orbital factories that spin around the equatorial belt. Ships of the Warfleet Solar are based in these huge floating docks, and other craft from all over the Imperium visit what are the largest man-made objects in the entire galaxy.

As the first hives ever built, the Martian factory hives are ancient and all are at least partially ruinous. Some areas are well maintained, and there are many new areas of building. Areas that are no longer used are simply allowed to rot.

A journey through the internal travel tubes would take a person from extremes of new construction to ancient industrial wastes. The travel lines weave between shiny new building piles, with their nets of steel bracing like the rigging of a sailing ship, passing into older darker zones where broken condensation traps spill their vaporous contents and enmesh speeding tube liners in a perpetual fog. Wastelands cover vast parts of the cities, deserts of broken plasteel slabs and twisted girders, with the occasional solitary tower pointing purposelessly towards the pink Martian sky.

Planetary Governor: The Fabricator General of the Adeptus Mechanicus, one of the High Lords of Terra.

Planet Type: Forge World.

Regime: Cult Mechanicus.

Defence: Ultra Formidable.

Notable History: Mars is the planetary realm of the Adeptus Mechanicus, the home and domain of the Tech-Priests of the Cult Mechanicus. The Red Planet is acclaimed as one of the wonders of the galaxy, the workshop of the Imperium, the forge-world, the maker of ships, and the guardian of secrets. It is the Adeptus Mechanicus who furnish the technical knowledge of the Imperium, preserve the scientific secrets of former times, and who explore the new sciences of the 41st millennium.