A Capitol Imperialis is a tracked Super Heavy Tank often used as a mobile command base for Imperial Guard Regiments. Though heavily armoured and protected by Void Shields, its sheer size and slow speeds limits the vehicle to defensive operations.
At almost fifty meters tall, the rhomboid-shaped Capitol Imperialis rivals a Titan in size.[2a] Solid adamantine plating and six Void Shield generators gives it a comparable level of protection. Its primary weapon is the massive Behemoth Cannon, so large that four Leman Russ Battle Tanks could fit within its barrel.[2a] The concussive force of firing the Behemoth Cannon can knock nearby troops off their feet and cause avalanches, while a single hit can kill thousands of enemy soldiers and vehicles, throwing them hundreds of meters into the air and producing a huge mushroom cloud.[2b][2e] Secondary weapons include hundreds of Bolters for close-in defensive fire, and the hull can be electrically charged to repel boarders.[2e]
Within its massive hold a Capitol Imperialis can carry two full companies of Imperial Guard, whether infantry or tanks. This allows the vehicle to act as a mobile bunker for troops, especially on inhospitable worlds, and the embarked soldiers can further support the Capitol Imperialis by fighting from its protective bulk.
The command bridge situated deep within a Capitol Imperialis allows its regiment's commander the tools needed to command his troops efficiently. Vox-gear, pict-casters, logic-engines and a holo-map, all serviced by hooded Servitors, gather, analyze and display information to allow the leadership to plan out their campaign.[2d]
When a tendril of Hive Fleet Leviathan threatened the world of Tarsis Ultra, one of the regiments sent to defend the planet against the Tyranids was the 10th Logres Regiment, led by Colonel Octavius Rabelaq. Colonel Rabelaq commanded the 10th from a Capitol Imperialis, which took part in the defense of the capital city Erebus. Firing from behind the trench lines protecting the city, the huge war machine was able to rack up an impressive kill count of Tyranids with the Behemoth Cannon. However, when the 993rd Death Korps of Krieg was threatened with being overrun during a rearguard action, Colonel Rabelaq charged his vehicle into the enemy.[2e]
While his act of heroism saved the Krieg regiment from destruction, Colonel Rabelaq found himself trapped as thousands of Tyranids threw themselves into the Capitol Imperialis' tracks, immobilizing it. At that moment a Bio-Titan appeared and took a direct hit from the Behemoth Cannon, severely wounding the creature. However, the Bio-Titan's preternatural regenerative abilities healed it of its injuries, and before another shell could be loaded it slammed into the Capitol Imperialis, knocking the war machine on its side. As the Bio-Titan tore open the vehicle, Colonel Rabelaq gave the order for the city's defensive cannons to fire on his vehicle's exposed plasma reactor. The resulting explosion vaporized everything within five hundred meters, creating a deep crater within which the fatally-wounded monster died.[2f]
Another Capitol Imperialis, the Lex Tredecim[3b] formed part of the Ultramarines' muster on Calth during the Invasion of Ultramar in 854999.M41. Sergeant Learchus Abantes, who had never visited Calth before, believed that the vehicle was too large to enter the planet's underground cave system, but Uriel Ventris returned that Calth's caverns were so enormous that the vehicle could move quite freely.[3a]
- 1: Armies of the Imperium, pg. 62
- 2: Warriors of Ultramar (Novel) - The Ultramarines Omnibus by Graham McNeill
- 3: The Chapter's Due (Novel) - Ultramarines: The Second Omnibus by Graham McNeill