The High Lords of Terra collectively form the Council of the High Lords of Terra, also known as the Senatorum Imperialis. The Senatorum is an Imperial governing body comprised of the twelve highest-ranked officials of the most powerful Adepta of the Imperium of Man. This body carries out the day-to-day decisions required to govern the Imperium in the Emperor of Mankind's name. The task of the High Lords is to interpret and enact the will of the Emperor. Accordingly, the position of High Lord is the most politically powerful in the Imperium. Since the Emperor can no longer govern his empire directly, it is the claim of the High Lords that his immortal will is known to them and the Emperor thus rules through the High Lords of Terra. Though the Imperium is too vast to be centrally governed, the High Lords ultimately make decisions affecting the lives of trillions of Imperial citizens across the galaxy.
The High Lords of Terra are the governing body of the Imperium of Man. They are tasked with interpreting the Emperor's will and enacting his rule across the largest empire in the galaxy. On their command, the fleets and armies of the Imperium move, only their edict can approve a Space Marine Founding, and on their orders, the Black Fleet sails and their grim tithes are collected. The Senatorum Imperialis has, at its roots, many echoes from human ruling bodies formed before the birth of the Imperium. In the beginning of the Age of the Imperium, the Emperor Himself ruled, although he formed about him a council of advisors, called the Council of Terra, that was comprised of key individuals. This top circle contained the Fabricator General of Mars, the Paternova of the Navigator Houses and Malcador the Sigillite, perhaps the Emperor's greatest ally during the Unification Wars of Terra. As the Emperor left the homeworld of Mankind to lead the Great Crusade, He left in His stead the legendary Malcador, more or less to act as Regent of Terra.
Over the course of the Great Crusade which reclaimed the galaxy and freed Humanity from enslavement, the Emperor discovered the lost Primarchs and brought them into the fold. As the Great Crusade began to branch off in many new directions, the Emperor grew to rely on his new War Council. After the decisive victory during the Ullanor Crusade, when Mankind's re-ascension was no longer in doubt, the Emperor decided to leave the Imperial war effort in the hands of his Primarchs under the command of the newly-proclaimed Warmaster Horus and return to Terra to carry out the next phase in the creation of the Imperium of Man -- creating a human version of the Eldar's Webway. At the same time, the Emperor decided that the Imperium could no longer be ruled directly by him and a council comprised of the Primarchs, instead, the ordinary mortals of the Imperium must also be allowed some say in its management. To this end, the Emperor created the Council of Terra to carry out his decisions and to handle many of the lesser administrative and bureaucratic tasks that did not require the Emperor's immediate attention. The Primarchs were left in control of the War Council of the Imperium, which was led by Horus and now had true power only over the direction of the Great Crusade rather than over the Imperium as a whole. The decision proved to be exceedingly unpopular with the Primarchs, who disliked relinquishing their say over the direction of the Imperium to the control of men and women whom they viewed as far less capable than themselves. This issue would be one of the festering resentments that allowed Chaos to corrupt the Space Marines of the Traitor Legions and turn them against the Emperor.
Following the calamities of the Horus Heresy, the Emperor was interred upon the Golden Throne and could no longer rule his realm directly. Several legends tell of the Emperor's last words, spoken as he was attached into the vast machinery that would allow his mind to live on. Full of foresight beyond mortal men, the Emperor's final instructions were for the rule of Mankind's galaxy-wide kingdom. In that time of great change, Malcador too was now gone, and it had been he who had proven best able to enact the Emperor's vision. Now that role, and the leadership for the coming reformation, fell upon Roboute Guilliman, the great Primarch of the Ultramarines. It was he who set up the new ruling body, the Senatorum Imperialis, or as it is more commonly known now, the High Lords of Terra. It was their duty to interpret the will of the Emperor and, in his stead, to command the Imperium. The number of this ruling council was set at 12, with Roboute Guilliman himself taking a seat under the title of Lord Commander of the Imperium, the old term Warmaster having fallen out of favour for obvious reasons.
Birth of the Imperium
Following the Horus Heresy, the Senatorum Imperialis of the High Lords of Terra succeeded the Council of Terra as the main executive body of the Imperium as part of the reformations initiated by the Primarch Roboute Guilliman, who joined the Council as Lord Commander of the Imperium, commanding the entirety of the Imperial armed forces. In the early 32nd Millennium, the rise of the Imperial Creed and the Cult of the Saviour Emperor to become the state religion of the Imperium meant that the Ecclesiarch of the Adeptus Ministorum was granted a seat, which soon became permanent. In the 36th Millennium, High Lord Goge Vandire, Master of the Administratum, lead a coup d’état and also became the Ecclesiarch of the Adeptus Ministorum, holding dual leadership over the two most powerful Adepta of the Imperium. During his Reign of Blood in the Age of Apostasy, the High Lords were powerless to act. When Fabricator General Gastaph Hediatrix demanded that the High Lords finally account for themselves and execute Vandire, Goge dissolved the Senatorum Imperialis and declared the Space Marines and Adeptus Mechanicus to be Traitors to the Imperium. Before long, Goge was slain by his own bodyguards, the Brides of the Emperor (who would become the Adepta Sororitas), after Loyalist forces led by the reforming Ecclesiarchy priest Sebastian Thor launched an invasion of Terra to bring Vandire down. The High Lords of Terra returned to power after the Senatorum Imperialis was restored, though major reformations, including the creation of the Ordo Hereticus of the Inquisition, were carried out to prevent any one man from ever again seeking to replace the Emperor as the true ruler of Mankind.
The High Lords
Since the dark days of the Horus Heresy, the number of seats on the Senatorum Imperialis has largely remained the same, fluctuating during various points of crisis before eventually returning to its original number. Each seat is filled by a leader from one of the most powerful Adepta and other organisations of the Imperium. A complex web of tradition, skulduggery, promises of support, threats of retaliation and considerations of mutual interest binds them together and determines who holds office and who does not. In practice, some of the Imperium's Adepta and institutions are so powerful and vital that it would be unthinkable for their leader to not be granted a seat amongst the High Lords of Terra. Naturally, over the long millennia, the unthinkable has happened many times over, however, and the existing High Lords often put in place an inordinate amount of measures to ensure that their seat is a permanent one -- that upon their deaths their position is automatically filled by the new head of their organisation. The following offices are almost invariably represented as High Lords because they form the cornerstones of the Imperium, the most important of its ancient institutions.
Although the sources regarding the exact composition of the Senatorum Imperialis are varied, some institutions and organisations within the Imperium are so powerful that their leaders can be considered a de facto High Lord. The following nine offices are almost always represented as High Lords:
- The Master of the Adeptus Administratum
- The Representative of the Inquisition
- The Ecclesiarch of the Adeptus Ministorum
- The Fabricator-General of the Adeptus Mechanicus
- The Grand Provost Marshal of the Adeptus Arbites
- The Paternoval Envoy of the Navigators
- The Master of the Astronomican
- The Grand Master of the Officio Assassinorum
- The Master of the Adeptus Astra Telepathica
These nine posts are virtually sacrosanct, and there are very few times in the history of the Imperium when their seats upon the High Lords of Terra became empty and were not filled with a successor from the same organisation. Note that a specific Inquisitor does not typically hold the position of Inquisitorial Representative on his own, but instead, the seat is retained for whichever individual is sent on behalf of the Inquisition during a meeting of the Senatorum. The eldest Grand Master of the Grey Knights is also occasionally present as the Inquisitorial Representative. Similarly, the place of the Paternoval Envoy is open to whoever might be the Envoy of the Paternova of the current ruling family of Navigators. The Paternova himself never leaves the Palace of Navigators, for it is forbidden for him to do so. To prevent a monopoly on power, the strongest Navigator houses usually agree to elect a Paternova from the weakest Navigator houses. If a strong house were to rise to power in the Council, that house would gain control of the Navigator's voice in the Imperium and thereby control all but the strongest Navigator families.
The total number of High Lords is said to be twelve, leaving three non-permanent openings. These positions are most often filled from among the following powerful Imperial leaders:
- Lord Commander of the Segmentum Solar
- Lord Commander Militant of the Imperial Guard
- Lord High Admiral of the Imperial Navy
- Cardinal(s) of the Holy Synod of Terra
- Abbess Sanctorum of the Adepta Sororitas
- Captain-General of the Adeptus Custodes
- Chancellor of the Estate Imperium
- Speaker for the Chartist Captains (representative of the Imperium's merchants)
It is an oddity that, throughout its history, very few members of the Adeptus Astartes have served as High Lords of Terra -- given the importance of humanity's most elite fighting force and the fact that the first council was initiated by Roboute Guilliman, the Primarch of the Ultramarines. This seems to have been set up intentionally by Guilliman, who knew that at times of great need, Space Marine leaders would have no choice but to step in, but would otherwise remain outside the ruling structure. Some say the Primarch's discouragement of Space Marines serving in the Senatorum Imperialis was based upon the Emperor's original Council of Terra -- which was separate from his War Council, and a ruling body that did not include any members of the Adeptus Astartes. Guilliman clearly believed, as his great work, the Codex Astartes points out, that it is the Space Marines' duty to serve Mankind, not to rule it, just as the Emperor Himself held.
In its long existence, the Senatorum Imperialis has gone through many changes. The High Lords have been forced to give one of its seats over to a religious leader (the Ecclesiarch, who joined shortly after the Adeptus Ministorum was named the sole state religion of the Imperium in the early 32nd Millennium), wiped out to a man by assassination (on the orders of a slighted Grand Master of the Officio Assassinorum, an event known as [[Beheading, The|"The Beheading"), and dissolved altogether by the ruling Ecclesiarch (during the civil war known as the Age of Apostasy). Many members have disappeared under suspicious circumstances and the Inquisition has been asked to investigate a number of times (although many have suggested that at least some missing High Lords of Terra have disappeared because of the Inquisition). Yet always, despite the many power struggles and strife, the High Lords of Terra have continued to interpret the Will of the Emperor and thereby rule the greatest empire in the galaxy.
- Battlefleet Gothic 41st Millennium, pg. 86
- Codex: Assassins (2nd Edition), pg. 24
- Codex: Chaos Space Marines (3rd Edition, 2nd Codex), pg. 7
- Codex: Grey Knights (5th Edition)
- Codex: Imperialis (2nd Edition) by Rick Priestley, pp. 13-14
- Codex: Orks (4th Edition), pg. 92
- Codex: Sisters of Battle (2nd Edition), pp. 5, 13, 16
- Codex: Space Marines (6th Edition)(Digital Edition), pp. 36, 85, 100,
- Codex: Ultramarines (2nd Edition), pg. 8
- Codex: Witchhunters (3rd Edition), pg. 45
- Dark Heresy: Blood of Martyrs (RPG), pp. 9, 12, 14, 17, 22
- Dark Heresy: Daemon Hunter (RPG), pg. 7
- Deathwatch: Core Rulebook (RPG), pp. 12, 285, 297, 323, 331-332
- Deathwatch: Rites of Battle (RPG), pp. 13-16, 38, 54, 65, 98, 247
- Deathwatch: The Achilus Assault (RPG), pp. 12, 14-15, 22, 102, 110, 119
- Horus Heresy: Visions of War
- Warhammer 40,000: Rulebook (6th Edition), pg. 403
- Warhammer 40,000: Rulebook (5th Edition), pg. 124
- Warhammer 40,000: Rulebook (4th Edition), pp. 9-10, 92
- White Dwarf 293 (UK), "Index Malleus: The Blood Pact", pg. 57
- White Dwarf 140 (UK), "Space Fleet: Additional Background, Rules, Data Cards & Counters", pg. 50
- False Gods (Novel) by Graham McNeill
- Legion of the Damned (Novel) by Rob Sanders, pg. 11
- Wolfblade (Novel) by William King, pp. 32, 37, 70, 104