Exercitus Imperialis

The Exercitus Imperialis, commonly known by their Low Gothic name, the ' Imperial Host ', are a 26th Founding Successor Chapter, created from the lineage of the stalwart and heroic Ultramarines. Adopting combat styles perfected by their predecessors of the Silver Centurions, they excel in phalanx infantry formations covered with overlapping fields of fire from their tactical and devastator squads with armoured support from their formations of Astartes Battle Tanks. They have defended the western borders of Segmentum Ultima since their inception, becoming experts in breaching operations and open field warfare in the process.

Chapter Home World
Alysium, fortress world and capital of the Sinistral-Ultima Sector in the Segmentum Ultima, stands vigilant against the western border of the Segmentum Ultima. When the Imperial Host was founded, the High Lords of Terra gifted them defense of Segmentum Ultima's western border to alleviate the pressure of the Segmentum's many responsibilities including increasing raids by orks, a newly discovered race of sentient beings in the T'au, the emergent Tyranid threat, and the constant Chaos incursions of distant star systems. Alysium is a temperate world, dotted by massive fortifications and anti-orbital batteries, but in the distant north of the planet, the Imperial Host reside within the Castra Albus, their fortress-monastery.

Fortress-Monastery
Castra Albus, a fortress stylized from the ancient Romanae castles of old on distant Terra, houses the Imperial Host Chapter. Designed by expert artisans of the Adeptus Mechanicus and overseen by members of the Ultramarines Chapter, it is a fortress that so rightly deserves its name of Warden of the West being built with strong walls of adamantium and constructed among the northern peaks of the Alpreggian Mountains.

Chapter Recruitment
The Imperial Host has a curious recruitment style of its aspirants. All members of the Chapter are recruited in squads of ten. They are then tasked with surviving upon the surface of Alysium with no aid of any kind, without clothing at the start of the trial, without supplies, for one year. If one of the aspirants does not pass the Trials of Survival, then none of the aspirants pass and they are given the choice of Chapter Serf or rejection of service with the Chapter. If they survive the Trials, they are then assigned a squad speciality, given to them by the Reclusiarch, based upon their aptitudes decided during the Selection process.

Officer Ranks

 * Legatus: Chapter Master
 * Praefector: Force Commander
 * Centurion: Company Captain
 * Dominar: Senior Lieutenant
 * Optio: Junior Lieutenant

Specialist Ranks

 * Magus: Chief Librarian
 * Magistor Primus: Master of Sanctity
 * Medicae Primus: Chief Apothecary
 * Artificor Primus: Master of the Forge
 * Lord Admiral: Master of the Fleet
 * Evocator: Captain of the Evocati
 * Praetor: Chapter Champion, Captain of the Honour Guard
 * Aquillor: Chapter Ancient

Line Ranks

 * Legionary
 * Acolyte
 * Initiate

Specialist Formations

 * Triarii: The most experienced legionaries of the Chapter aside from the members of the Evocati. They are a melee oriented formation equipped with breacher shields and their famous Auric Spears. Reinforced power armour gifts them the ability to withstand punishing assaults on the frontlines, only being surpassed by the Evocati's Tactical Dreadnought Armour. They are organized into ten man squads and are attached to all existing cohort squads providing every unit with a dedicated melee capabilities.
 * Praetorian Order: The Imperial Host's dedicated Honour Guard. Formed in echo of their progenitor's own Honour Guard, they are numbered at one hundred members dispersed among the Cohorts in squads of twenty.
 * Evocati: Veteran legionaries awarded with the Crux Terminatus.

Order of Battle
The Exercitus Imperialis is mobilized by Cohort, a company sized element of 200 Astartes with the bulk belonging to the Hastati Close Combat Squads. Each Cohort is led by a Centurion with a Dominar and an Optio serving as his junior officers. Each Cohort is also given five specialists from each one of the disciplines of the Chapter including: Artificors, Medicaes, Librarians, Magistors, and a squad of Honour Guard from the Praetorian Order. Evocati Terminator Squads are also dispersed throughout the Chapter with the bulk of them remaining in the 1st Cohort as per the Codex Astartes. Each Cohort is further reinforced with an armour and light vehicle element maintained by the Artificors of the Chapter and a scout element whether they be of original gene-stock or that of a Primaris equivalent.

Chapter Gene-Seed
Since the Exercitus Imperialis Chapter hails from Ultramarine lineage, corruption or genetic flaw with gene-seed samples is an extreme rarity. The Trials of Survival also help to weed out any aspirants whose individuality or personal feelings could or would harm their fellow aspirants. The unfortunate side effect of this being that those who would be worthy are denied the chance of becoming an Astartes due to one individual's actions or mindset. This consequence of action further explains the Chapter's ethos that one individual affects the entire whole of the Chapter whether he intends to or not, no matter his motivations.

Primarch's Curse: (Honour the Codex)
The Exercitus Imperialis heavily rely upon the Codex Astartes for most of their combat decisions even though they are a Divergent Chapter. They organize themselves a little differently and approach combat in a slightly different manner but most of their engagement decisions are based upon the ''Codex. ''They do not, however, regard the Codex Astartes as a holy text as some Ultramarines Successors tend to do. They instead use it as a gauge on how to treat other Chapters of the Imperium, in the process giving themselves an air of superiority for being an Ultramarine descendant. The return of Primarch Roboute Guilliman has only further exacerbated this problem.

Chapter Fleet
Fleet Group Capris: 1st Cohort Fleet Group Aqros: 2nd Cohort Fleet Group Prises: 3rd Cohort Fleet Group Leonius: 4th Cohort Fleet Group Taros: 5th Cohort
 * Capris: Strike Cruiser
 * 4 Lunar Class Cruisers
 * 5 Gladius Class Frigates
 * 3 Nova Class Frigates
 * 2 Hunter Class Destroyers
 * Aqros: Strike Cruiser
 * 3 Lunar Class Cruisers
 * 1 Vanguard Class Light Cruiser
 * 8 Gladius Class Frigates
 * 2 Nova Class Frigates
 * Prises: Strike Cruiser
 * Leonius: Strike Cruiser
 * 2 Lunar Class Cruisers
 * 2 Vanguard Class Cruisers
 * 5 Gladius Class Frigates
 * 2 Hunter Class Destroyers
 * Taros: Strike Cruiser

Chapter Relics
The Exercitus Imperialis maintains several relics gifted to them by allies within the Imperium, most notably the Ultramarines Chapter as well as the Silver Centurions. From the Ultramarines they received fifty suits of Cataphractii Tactical Dreadnought Armour for their Evocati formations and from the Silver Centurions they were awarded one hundred shields and spears for their Triarii formations. Upon the Exercitus Imperialis Chapter’s founding day they were given five Sicarian Battle Tanks. One for each Cohort within the Chapter to have, awarded by the Adeptus Mechanicus contingent upon Macragge.

Chapter Colours
The Exercitus Imperialis primarily wears silver coloured power armour with the exception of both backpack vents, shoulder pauldron trims and poleyns (knee guards) being light gold in colour. The Aquila or Imperialis worn on the plastron (chest guard) is also gold in a colour. A white coloured squad specialty symbol (Tactical, Devastator, Assault or Veteran) stenciled upon the right shoulder pauldron or right poleyn, indicates an individual battle-brother's assigned squad specialty. A small white coloured roman numeral stenciled next to the squad specialty symbol indicates squad assignment, while the larger white coloured roman numeral stenciled upon the left poleyn indicates company assignment.

Chapter Badge
The Exercitus Imperialis' chapter icon consists of a stylised black skull centered within a white circlet surrounded by a black border, which is enclosed within a gold coloured, ancient Grecian-style border. The skull has a small white 'Ultra' symbol centered upon its forehead, indicating the Chapter's heritage from the Ultramarines.

Allies

 * Ultramarines
 * Silver Centurions
 * Void Walkers

Enemies

 * Death Guard
 * World Eaters
 * Hive Fleet Behemoth
 * Iron Warriors
 * T'au Empire
 * Orks of Golgotha