Officio Assassinorum - Founding of the Officio Assassinorum: When the Emperor spoke this famous declaration during the early years of the Great Crusade, a number of his most loyal servants met, eager to help enact his dreams of uniting Mankind across all the settled worlds of the galaxy. These men and women were highly skilled in the craft of stealth and subterfuge and highly accomplished in the arts of death.They hunted down those who would bring ruination to the Emperor's plan for Human betterment. In secrecy they acted, preferring not to receive praise from the Emperor for their actions, for they felt themselves unworthy of such attentions amidst the great sacrifices and destruction caused by the ongoing operations of the Great Crusade. They carried out their executions silently, moving unseen from world to world in the wake of the Emperor's conquest, ensuring that promises made to the Imperium by rulers newly brought into Imperial Compliance were not reneged upon, that newly installed planetary governors remained loyal, and that treaties and pacts were enforced.In time, these servants realised that they could not hide from even their own deaths forever, and that their skills must be passed on to a new generation if their great work was to continue. Thus, they finally revealed their existence to the Emperor. He saw, sorrowfully, the necessity for their existence and the terrible duty that they had taken upon themselves and he was most pleased. Great temples were constructed and the most skillful and deadly youths were sought out to train at them.Thus was the Officio Assassinorum created in secret, and the names of Callidus, Venenum, Culexus, Vindicare, Eversor and Vanus were forever immortalised. The strongest survived their rigorous training, and in turn passed on their skills to others. New skills were learnt and new temples of death were later founded; the art of blade and pistol, poison and garrote were honed in every aspect conceivable. So it is that there is no world in the galaxy beyond the Emperor's rule; no enemy beyond the Emperor's wrath.During its early history all six Assassinorum Temples, then known as "clades", were located on Terra. Each clade was led by an official known as its "director primus." The Officio Assassinorum was created during the Great Crusade in the 30th Millennium by Malcador the Sigillite, the Regent of Terra, who served as its first overall leader or "Grand Master of Assassins" on the order of the Emperor. The Assassins of all 6 existing clades were tasked by the grand master and their founding directors primus with carrying out the Imperium's goals in those circumstances where unleashing the full military forces of the Imperium would prove unwise or too costly.The Assassinorum clades came into their own during the Horus Heresy of the early 31st Millennium, when they were tasked with eliminating the rebel Warmaster Horus and other leaders of the forces of Chaos; these missions met with only mixed success as the brutal history of that period all too amply demonstrates.However, after the Wars of Vindication which took place shortly after the death of High Lord Goge Vandire during the Age of Apostasy in the 36th Millennium, a renegade Callidus Assassin by the name of Tziz Jarek attempted to assassinate the Grand Master of Assassins of that era. After a series of terrible atrocities that were precipitated within the Imperial Palace itself, the Assassin temples were split up and distributed across the width and breadth of the galaxy.This was to ensure that should one fall to alien influence, Daemonic influence, or other heresy, the others would remain untainted. Similarly, a hidden ordo of the Inquisition was implemented, known as the Ordo Sicarius, to monitor the Officio Assassinorum, and its power was drastically limited -- assassinations could only be performed after receiving a 2/3 vote from the Senatorum Imperialis of the High Lords of Terra. All Assassins were to give detailed accounts of their mission activity, subject to Inquisitorial inspection at any time. Lastly, all Assassins (with the exception of those of the Eversor Temple) were to undergo regular psycho-indoctrination, again under the scrupulous eyes of the Inquisition if deemed necessary.