Mars

Mars, also known as the “Red Planet,” is the first and greatest Forge World — the “Forge World Principal” — of the Imperium of Man. It is located in the Sol System of the Segmentum Solar, and produces vast numbers of weapons, vehicles and other advanced technology for the Imperium and its war efforts throughout the galaxy. Mars is also the homeworld and headquarters of the Adeptus Mechanicus and a planet sacred to the faith of the Cult Mechanicus, which is one reason why travel to the Red Planet for Imperial personnel who are not members of the Mechanicus and share its peculiar faith is restricted. The Red Planet is the birthplace of the Cult Mechanicus.