Adeptus Mechanicus

The technological base of the Imperium of Man, the Adeptus Mechanicus has preserved, recovered, and developed what remains of humanity's techologic achievements after the Dark Age of Technology.  They are also responsible for maintaining the Emperor's Golden Throne.  Founded as a separate institution on the ancient Forge World of Mars, the Mechanicum as an entity joined the fledgling Imperium as an ally and equal, after the entreaty of the Emperor.  To this day, the Adeptus Mechanicus maintains a significant level of autonomy from the High Lords of Terra - for it is their mastery of forgotten arcane mysteries of Standard Template Constructs and the techniques and maintenance of -all- of the Imperium's war materiel. In Warhammer 40000, the forces of the Adeptus Mechanicus include

• Skitarii - Cybernetic warriors, these troops fill out the ranks of the Mechanicum's forces
• Electro-Priests - fanatical servants of the Machine God, filled with his Motive Force and shocking amounts of electricity
• Tech-Priest Dominus - Masters of the Cult Mechanicus, these Headquarters troops can wreak havoc upon both Infantry or Vehicles of the enemy
• Kastellan Robots - Technologies over 10000 years old, the Kastellans represent the ability of the Cult Mechanicus to repurpose unknown tech for servitude and destruction.
• Onager Dunecrawler - a walking tank, perfectly suited for the irradiated dunes of the Forge World of Mars, and for combat on far-flung worlds.
• Imperial Knights - last but most certainly not least, the Adeptus Mechanicus is crucial for supporting and maintaining the different Imperial Knights - be they Freeblade, or House Knights.  All types of Knight, Knight Castellan, Knight Valiant, Knight Warden, Knight Crusader, and even the smaller Armiger Helverins and Armiger Warglaives depend greatly upon the support of the Tech-Priests of Mars.