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Administratum Icon

The icon of the Adeptus Administratum

The Master of the Administratum is the High Lord of Terra who serves as the top official of the Adeptus Administratum, the governing bureaucracy of the Imperium of Man. The individual who ascends to this rank is always one of the nine permanent members of the Senatorum Imperialis. The Master of the Administratum is also the titular head of the Departmento Munitorum which handles all of the logistics of the Astra Militarum, though in practice he or she must also share influence over that bureaucracy with the Lord Commander Militant of the Imperial Guard and other high-ranking Imperial military officers.

At least in name, the Master of the Administratum is perhaps the most powerful man or woman in the galaxy, as he or she controls the portion of the Imperial government that is most crucial in the day-to-day functioning of an interstellar state -- its bureaucracy. In truth, the Master of the Administratum handles none of the day-to-day affairs of bureaucratic governance; the role is primarily concerned with ceremony, public relations and the constant political infighting which generally consumed the High Lords of Terra before the return of the Primarch Roboute Guilliman as ruling Lord Commander of the Imperium in 999.M41.


In the wake of the Horus Heresy, the Reformation of the Imperium initiated by Roboute Guilliman during his first stint as Lord Commander of the Imperium created the Adeptus Administratum by officially aggregating all of the various Imperial military and civilian bureaucracies created under the auspices of the original War Council and Council of Terra during the Great Crusade. By its very nature at the head of the Imperial bureaucracy, the office of the Master of the Administratum emerged for the first millennium of the Imperium's history as the most politically powerful office of state, as long as that state remained officially secular in character. After the emergence of the Adeptus Ministorum as the official state church of the Imperium in the middle of the 32nd Millennium, the Ecclesiarch who lead the faith overtook the Master of the Administratum as the most powerful among the High Lords of Terra in practice. This culminated in the 36th Millennium during the Age of Apostasy with the rise of Goge Vandire, whose use of assassins and the manipulation of Ecclesiarch Paulis III ultimately allowed him to become both the Master of the Administratum and the Eccleisarch of the Ministorum, threatened to transform the stable theocratic oligarchy the Imperium had become into a true dicatorship. His assassination at the hands of Alicia Dominica and her Brides of the Emperor ended this threat to the realm. The Adeptus Astartes and the Inquisition's newly formed Ordo Hereticus dismantled the overweaning military power of the Ministorum and restored a balance between the Administratum and the Ministorum that lasted more or less intact until the return of Lord Commander Guilliman in 999.M41.

Notable Masters of the Administratum[]

  • Tobris Ekharth - Tobris Ekharth was the Master of the Administratum and a powerful member of the High Lords of Terra in the middle of the 32nd Millennium during the War of the Beast. Blind in one eye due to a wound that had left a long scar across his face, Ekharth was close to the powerful Lord High Admiral Lansung and one of the key members of the political alliance led by Lansung that ensured his dominance on the Senatorum Imperialis. During the war against The Beast, the ruling triumvirate of Lansung, Ekharth, and Lord Commander of the Imperium Udin Macht Udo ensured Imperial inaction and internal squabbling to maintain their own power over the status quo. Following Lansung's fall from grace after the appearance of the Ork Attack Moon over Terra, Ekharth abandoned his former ally and instead pledged his support to Juskina Tull and her disastrous Proletarian Crusade. Ekharth again abandoned his ally, this time Lord Commander Udin Macht Udo, when he was overthrown by Imperial Fists Chapter Master Koorland and the Inquisition. Later, Ekharth met with the Grand Master of Assassins Drakan Vangorich, and pleaded with him to do something about the Adeptus Astartes' usurpation of power from the High Lords. Vangorich regarded him only with disgust. When the Salamanders Primarch Vulkan unexpectedly returned to lead the Imperium against The Beast, Ekharth was horrified when the Primarch broke Imperial protocol and utilised Administratum resources without his approval. Despite his timid protests, he was ignored by both Vulkan and Koorland as a weak and self-interested man. Ekharth again led opposition to Koorland alongside the Ecclesiarch Erekart Veneris Sanguinan Mesring, this time to try and prevent the creation of the Deathwatch, which he believed would further enhance the power of the Adeptus Astartes. However when the Ork Attack Moon over Terra reactivated, Ekharth realised he could not stand in the way and ended his political opposition. After the war, Ekharth sought to oppose Vangorich and Inquisitorial Representative Marguerethe Wienand in naming the Imperial Fists Chapter Master Maximus Thane as the new Lord Commander of the Imperium. However, he was again overruled and chose not to fight the appointment. Ekharth was among the High Lords killed by Vangorich in The Beheading. The method of his death is unknown, but he was replaced with an impostor who likely was a Callidus Assassin. This impostor later murdered Ekharth's allies, Lord Commander Militant Abel Verreault and Lord High Admiral Lansung and went on to serve as the Master of the Administratum in Vangorich's puppet Cabinet.
  • Simion Pentasian - Simion Pentasian was the Master of the Administratum during the last days of the Great Crusade and the Horus Heresy. A dour and humorless man, Pentasian was still a faithful servant of the Emperor who managed to hold together the vast and unwieldy Administratum of this era. During the Heresy, Pentasian fought against the attempts of the Tech-priest Vethorel, the ambassador to Terra of the Loyalist Fabricator-General Zagreus Kane who had emerged in the wake of the Schism of Mars, to promote the Mechanicum to full Adeptus status, which would provide the Priesthood of Mars a formal seat on the Council of Terra. Though successful at the time, the Mechanicum was eventually reorganised as the Adeptus Mechanicus and received a seat on the Senatorum Imperialis during the Reformation of the Imperium.
  • Goge Vandire - The terrible conflicts of what Imperial savants now name the Age of Apostasy grew out of a political struggle between the Administratum and the Adeptus Ministorum for dominance over the Imperium. The struggle known as the Reign of Blood began when control over the Imperium's government was essentially seized by a single man, the High Lord of Terra Goge Vandire, who commanded both the Administratum and the Ecclesiarchy and ruled the Imperium according to his own wishes instead of in accordance with the Emperor's will. Fortunately, his brutal reign eventually came to an end with the coming of the reforming preacher Sebastian Thor and his reborn Confederation of Light, a sect of the Imperial Cult based on the previous Confederation of Light's banned teachings, that sought to end Goge Vandire's corruption of Imperial theology. High Lord Vandire was in power for almost a standard century before finally being overthrown in the midst of the Terran Crusade and slain by his own bodyguards, the Daughters of the Emperor, who later became the Orders Militant of the Adepta Sororitas. Vandire was replaced as the Imperial Ecclesiarch by Sebastian Thor, who unleashed the Imperium's second major era of reform following the Horus Heresy. The end of the Reign of Blood resulted in a major reformation of the Ecclesiarchy, the creation of the Imperial Inquisition's Ordo Hereticus to police those enemies of the Imperium who lay within its own structures, and the creation of the Adepta Sororitas to serve as both the Ecclesiarchy's new military force and the Chamber Militant of the Ordo Hereticus.

High Lords of Terra (Senatorum Imperialis)
Permanent Members Master of the AdministratumInquisitorial RepresentativeEcclesiarchFabricator-GeneralGrand Provost MarshalPaternoval EnvoyMaster of the AstronomicanGrand Master of AssassinsMaster of the Adeptus Astra Telepathica
Rotating Members Lord Commander of the Segmentum SolarLord Commander MilitantLord High AdmiralCardinal(s) of the Holy Synod of TerraAbbess SanctorumCaptain-GeneralChancellor of the Estate ImperiumSpeaker for the Chartist CaptainsLord Constable
Ruling Member Lord Commander of the ImperiumImperial Regent


  • The Binary Succession (Audio Book) by David Annandale
  • Codex: Assassins (2nd Edition), pg. 24
  • Codex: Assassins (3rd Edition), pg. 10
  • Codex: Black Templars (4th Edition), p. 19
  • Codex Imperialis (2nd Edition)
  • Codex: Sisters of Battle (2nd Edition), pp. 13-14, 16, 18, 35, 39-42
  • Codex: Witch Hunters (3rd Edition), pp. 4, 6
  • Echoes of the Long War (Novel) by David Guymer, Ch. 18
  • I Am Slaughter (Novel) by Dan Abnett, Ch. 9
  • Predator, Prey (Novel) by Rob Sanders, Ch. 7
  • The Beast Must Die (Novel) by Gav Thorpe, Ch. 1
  • The Beheading (Novel) by Guy Haley, Ch. 13
  • The Hunt for Vulkan (Novel) by David Annandale, Epilogue
  • The Last Son of Dorn (Novel) Chs. 2-3
  • The Last Wall (Novel) by David Annandale, Chs. 5, 13
  • Watchers in Death (Novel) by David Annandale, Ch. 4