Adeptus Terra

The Adeptus Terra, also known as the Priesthood of Earth, is the government of the Imperium of Man. When we say government, however, we use this in the loosest sense of the term. In theory, the Adeptus Terra is the umbrella organization that all branches of the Imperial government belong to, serving under the God-Emperor of Mankind. In practice, the Adeptus Terra is extremely disunited, with member branches extremely distrustful of each other.

Organisation

Several organizations belong to the Adeptus Terra, though only in the loosest sense of the word:

• Adeptus Administratum - The penpushers. No, really.
  • Adeptus Munitorum - They are devoted to the general administration, supply and command of the many armies of the Imperium. With some exceptions of course.
    • Astra Militarum - The Hammer of the Imperium.
    • Militarum Tempestus - The smaller Hammer, more precise.
  • Departmento Exacta - The god damn Tax collectors.
  • Officio Assassinorum - When you need somebody extra-dead.
  • Estate Imperium - The secretariat. They had to keep and furnish records of Imperial organizations in all likelihood.
  • Imperial Fleet - Includes almost every ship in the Imperium. Except some specific fleets.
    • Navis Imperialis - The Imperial Navy, huge ships with big guns.
    • Merchant Fleets - Ensures trade between Imperial planets and sectors. The combined merchant fleets compose almost 90% of all the interstellar spacecraft in the Imperium. Just like in real life.
    • Civil Fleets - Contains privately-owned interstellar craft operating along routes licensed by the fleet authorities.
    • Navis Nobilite - Are responsible for guiding Imperial ships through the fucking Warp without getting lost and killed by its inhabitants.
  • Officio Logisticarum - Created by Roboute Guilliman himself, it oversees the task of organising and resupplying the Indomitus Crusade.
  • Officio Medicae - Deals with public health and medical-related issues, operating medical facilities throughout the Imperium.
  • Officio Agricultae - Has the massive charge of managing Agri-Worlds and food production.
  • Logis Strategos - The Imperial intelligence and analysis agency.
  • Astra Cartographica - Maps the stars.
  • Rogue Traders
  • Templars Psykologis - The Imperium primary military intelligence and psychological warfare branch. Maybe. We are not sure.
  • Officio Sabatorum - Responsible for the sabotage and disruption of the Imperium many enemies.
  • Planetary Governors - They are the individuals with the (often hereditary) authority to rule a world or even an entire star system in the name of the Emperor of Mankind. Known to fuck-up on a daily basis.
    • Planetary Defense Force - The very first line of defence in case of a planetary attack.
    • Enforcer Security Force - Your friendly neighbourhood police. If by "neighbourhood" you mean "planetary" and by "friendly" you mean "as violent as humanly possible".
  • Ambassador Imperialis - The diplomats. As you may have guessed, they are not very popular or well known within the Imperium.
• Adeptus Astra Telepathica - The main mean of communication of the Imperium.
  • League of Black Ships
  • Scholastia Psykana
  • Anathema Psykana
• Adeptus Astronomica - THE lighthouse.
• Adeptus Arbites - A mixed of the FBI, the SWAT and Judge Dredd.
• Adeptus Astartes
• Adeptus Custodes
• Adeptus Fidicius - Literally the IRS/HMRC.
• Synopticon - The Signals intelligence of the Imperium.
• Logos Historica Verita

Special cases

Though functionally independent, the Space Marines Chapters are officially part of the Adeptus Terra, as their loyalty is to the Emperor, who is the official head of the Adeptus Terra.

In the same way, whilst the highest and mightiest consider the Adeptus Custodes a nominal part of Adeptus Terra, the Dread Guardians of the Ten Thousand do not consider themselves apart of the Imperium at all, as part of the Imperial Household (the royal retainers and servants of the monarch) they exist outside of the Imperial apparatus of power.

The Logos Historica Verita is an interesting one. As the newest branch created by Roboute Guilliman, it is not clear where it should be placed in the organisation chart. But the most likely theory is that it is oversaw by the Primarch himself.

Where is the rest?

Though allied to the Adeptus Terra, the Adeptus Mechanicus is a separate organization which only has nominal ties to the Adeptus Terra. And despite wielding enormous power within the Imperium, the Ecclesiarchy and the Inquisition are officially not part of the Adeptus Terra.