The Imperial Inquisition is essentially evolution of the Imperial Intelligence. Renamed during the Great Crusade in part due to the great religious fervor that erupted after the Eastern Orthodox Catholic Church declared the Emperor Heraclius XX the Great a living Apostle and Son of God, the mission of the Imperial Inquisition is to guard the Imperium from attack of all forms from xenos and humans be it overt or covert, and to ensure internal stability of the Emperor's realm. The Imperial Inquisition's authority is incredibly extensive, and they answer directly to the Emperor himself. They do not have power over the Adeptus Astartes, since the power to command them lies under the Emperor and his Strategos Primus only, but they can request for their assistance. The Imperial Inquisition also has powers to directly negotiate with foreign powers, much to the consternation of the members of the Roman Curia in the Ministry of Foreign Affairs who regard them as near rogues. But such powers require the explicit authorization from the Emperor himself.
Supreme High Inquisitor Lord
The highest position an Inquisitor can attain, and also the much vaunted position of one of the Emperor's closest advisors. The High Inquisitor Lord provides the latest intelligence reports to keep the Emperor up to date on the latest matters of the galaxy, and also directs the Inquisition as a whole. The current High Inquisitor Lord is Inquisitor Gregor Eisenhorn.
High Inquisitor Lord
A High Inquisitor Lord is the head of an Ordos. Only those recognised for their excellence and dedication to service and far above their peers are given this title.
An Inquisitor Lord is often given responsibilities over a sector of space or less. Their job is to direct the operations of local inquisitorial operations, and to oversea any investigation that warrants their personal attention. He has cross-ordos authority, especially when there is need to mediate between the various ordos.
The Inquisitor is the title given to those who have passed the muster of Interrogator under another Inquisitor, who then petitions that the said Interrogator is promoted to the rank of Inquisitor. The Inquisitor is given the role of coordinating a group of Interrogators and others in his retinue. Typical Inquisitors are given roles and missions by the Inquistor Lords. Not all Inquisitors have the same mission profile. Some are destined to perform desk jobs, and coordinating and collecting information and redirecting them to the relevant persons. Some are actual field agents who perform missions and other tasks on the field.
The Interrogator is the starting rank that one gains when one first joins the Inquisition. There are many grades an Interrogator must attain before he has conferred and recommended the title of Inquisitor.
The Inquisition has under its own comamnd its own troops, who are in turn under the command of the Emperor himself. 5 million Imperial Guard and 100,000 Astartes are under the command of the Inquisition, and they are often very specialized troops. Astartes come in two types: Grey Knights and Deathwatch. The former are trained to take down powerful psykers, rare as they are. The latter are trained to fight xenos specifically. Grey Knights are naturally fewer than the latter. Imperial Guard troops often are heavily cyberneticized, tend to be more specialized than the average Imperial Guard unit, and thus use fewer armored vehicles. The Astartes legion often loan its own to the Inquisition if so required. The Inquisition operates its own small fleet of starships, ranging from stealthy shuttles, to Astartes destroyers and one Strike Cruiser (which typically are Astartes Legion warships on loan. This is rotated among the 3 legions every few years). It is expected that this fleet will expand in the near future.
The Inquisition has broad powers that distinguishes itself from other Intelligence Agencies. The Imprimatur granted by the God Emperor allows it to commandeer troops when necessary, and the Inquisition could call for the exterminatus of worlds if there is a threat that justifies the world's extinction.
The Inquisition is divided between various Ordos that specialise in many different areas. They fulfill many important functions, though many may overlap and it isn't often that cross-ordos investigations are conducted. Originally, there were two Ordos: Ordos Proditorius and Ordos Diplomatica. The rising need to combat many threats led to the Ordos Diplomatica to split into many different Ordos.
Charged with finding traitors within the Imperium, the Ordos Proditorius is the internal security arm of the Inquisition. Naturally, they suspect many to be potential traitors, but their close surveillance of all things within the Imperium, ensure that the Imperium's secrets are kept secret, and none may sabotage the Imperium in any way. Their tasks have become more difficult owing to the rise of heavily cyberneticized humans, and has led to close collaboration between the Ordos Proditorius and the Ordos Robotica when it comes to dealing with cyberneticized humans. Of late, the Ordos has taken note of pirates and slave traders beyond the Imperium and steps have been taken to combat these threats to the security of the Imperium.
What used to be under the Ordos Diplomatica to deal with Robotic races, became an ordos of its own right owing to the rise and spread of what some term as "Computer Intelligences", and nanotechnology. Cyberwarfare has also become such a powerful tool of warfare that the Ordos has to allocate resources to combat cyberwarfare threats. The Ordos also has its own plethora of cyberwarfare tools to retaliate against rogue attacks.
Another outshoot from Ordos Diplomatica, the Ordos Xenos' mission is to protect the Imperium from rogue xeno threats, and they are often at the forefront of the intelligence warfare with the Karlacks, and other xeno races. Of late, orc pirates have fallen under their radar, and Inquistorial agents go deep into the frontier seeking out the bases of these orcs and directing Imperial assets to persecute these xeno scum.
The Ordos Diplomatica, alongside the Ordos Proditorius, is the oldest of the ordos. Their mission is to gather intelligence for the Imperium, and many of their number are also ambassadors within the Ministry of Foreign Affairs. This naturally is kept secret, but an Inquisitor is highly prized for his or her intelligence and keen mind, and thus their usefulness as diplomats are boundless.
Known otherwise as the Order of the Hammer, the Ordos Malleus is tasked with defending the Imperium against rogue and enemy psyker attack. They work closely with the Ordos Proditorius as a result. They also focus their efforts on the research of psyker technology, and thus work closely with the Adeptus Mechanicus on many top secret projects. They are also responsible for the management of the Imperial Psykery Program, where psykers are identified from an early age and then drafted into the serv the Imperium and put through an intensive training program before they are allocated tasks in the service of the Emperor.
Otherwise known as the Order of the Assassins, the Ordos Sicarius' role is to send out assassins to kill the enemies of the Imperium. Assassins may come in many forms, from berserkers, to anti-psykers, to snipers, shape shifters, poisoners, or even hackers, the Ordos Sicarius is the most shadowy of all the Ordos of the Inquisition, and they answer only the Emperor himself.