Space Marines

The Adeptus Astartes (commonly known as Space Marines, and colloquially as Angels of Death) are the most elite and feared fighting forces of the Imperium. The primary unit of organization is the Chapter, a self-contained army fully equipped with its own transport, non-combatant support staff, etc. There are around a thousand Chapters, each comprising a thousand Space Marines. There are far too few Space Marines to form the Imperium's main military forces; instead they operate as highly mobile strike forces. They are entrusted with the most dangerous missions, such as lightning raids behind enemy lines, infiltration, and tunnel fighting. Through selection, training, and conditioning, Marines are physically, mentally, and spiritually superior to any other Imperial soldier.

Necromunda
As usual for a hive world, a token presence of Space Marines is stationed on Necromunda, in this case they are permanently based in Fortress Monastery on Hive Primus after an Ork invasion some years ago, and the planet provides many high quality recruits for the Adeptus Astartes of the Imperial Fists Chapter.1b, 1d, 1a

Recruitment
Like most hive worlds, Necromunda provides the Imperium with vast numbers of recruits for the Imperial Guard and even some of the Space Marine Chapters as part of Lord Helmawr's feudal obligations. This recruitment brings Imperial officials to Necromunda to inspect and sometimes conduct recruiting drives among the fighting gangs.1d, 1a, 2

Exceptional Clan warriors may be recruited into the Planetary Defence Force, Imperial Guard or even the Adeptus Astartes, which acts as a motivation for them to achieve a good reputation.1d

Fortress Monastery
The Adeptus Astartes maintain a permanent contingent on Necromunda are based in the Fortress Monastery, located high up on the side of Hive Primus (Necromunda's largest hive), near the Helmawr palace of the very top of the spire. From here the contingent can launch assaults when help is requested by Lord Helmawr. At the base of the Fortress Monastery is the high security docking area used by Space Marines and other important off-worlders, such as the Inquisiton, Adeptus Arbites and other Imperial dignitaries.1a, 2

Ork invasion
At some point in the past, Ork raiders captured and occupied a Cluster of three distant hives. All contact was lost for several years, but eventually the rest of Necromunda realised what had happened, and a campaign was mounted to clear the Cluster, including a contingent of Space Marines.

The hives were besieged and destroyed, with all that remains being three ruined hives, uninhabited and with their tops caved in the largest has become a famous landmark possibly worshipped by the local Nomads, called the Skull.

This was the original reason for the deployment of Space Marines on Necromunda, which has since become a permanently established presence based in the Fortress Monastery on Hive Primus.1a

Imperial Fists
The Imperial Fists are the main Chapter based on Necromunda today, and were called there originally to remove the Ork invasion presence. Necromunda is one of the two planets from which the Imperial Fists recruit new members, the other being Holy Terra.

Imperial Fistmas
Rumours exist that the Imperial Fists' primarch Rogal Dorn came to Necromunda along with his legion, and survive in the form of Imperial Fistmas, a holiday season for the citizens of Necromunda.

Blood Angels
The Blood Angels also have Marines stationed on Necromunda, who are identified by wearing black right shoulder pads. They often also wear an ornate golden left shoulder pad emblazoned with "Necromunda" below the Chapter Insignia to distinguish themselves.

They have been known to fight Scavvies in the Necromundan Underhive.1d, 3

Ultramarines
The Ultramarines too have a force based in the Necromundan Fortress Monastery.

During the bloody Genestealer revolt of the Nautilus spire in the Palatine Cluster's Acropolis Hive, Lord Helmawr asked for assistance from the Space Marine contingent based on Necromunda. In response, a task force of 35 Ultramarine Terminators led by Commander Darik launched their assault from the Fortress Monastery, to prevent the breakout of Genestealers from the spire and to kill the Primarch.

Equipment
Bolt guns are standard issue for Space Marines on Necromunda, as throughout the Imperium, and wear Power or Terminator armour.1c