Covenant Citadel

A Covenant citadel.

The citadel, sometimes known as occupation citadel or a forward operations citadel, is a Covenant base structure, and the Covenant equivalent of the UNSC Firebase. It contains a command center, seven modular building sites, and four turret foundations.

Overview

Design details

The citadel is a basic command structure deployed during interplanetary warfare or occupation campaigns. The citadel provides field command facilities for the commander of invading or defending Covenant forces to issue orders; it employs a modular system to build structures that support aggressive colonization as well as rapid deployment of troops and armor. Whereas UNSC Firebases and Banished Outposts are prefabricated and airlifted into the battlefield large transport craft such as the D20 Heron, D81-LRT Condor or Lich, Covenant citadels and their supporting sub-structures are teleported into the battlefield whole. From here, supplies are driven into the base via gravity lift and stored in the Warehouses. Once established, a large gravity lift is established in the front of the base, which can be used to move troops and vehicles to the front lines of the battle. The citadel does not appear to have any physical openings for which to enter or exit the base—troops simply use teleporters to enter and exit the base. When threatened, the base can lock down, which will establish a shield around the teleporter into the base to prevent unauthorised entry or exit into or out of the base.

Minibase

A Covenant Minibase on Arcadia.

The Covenant also made use of Minibases, smaller outposts only capable of supporting one additional structure. They were notably employed during the Battle of the Trove, where they were used as forward airbases with which to construct Oghal-pattern Banshees and Bkowe'nei-pattern Vampires. Unlike their UNSC counterpart, there is no structure for the building of the Covenant minibase to attach to; simply a teleporter pad on the ground for troops and supplies to use to enter the lone building.

Expansions

The citadel is capable of hosting up to seven modular structures, alongside up to four turret slots.

• Temple
• Warehouse
• Hall
• Factory
• Summit
• Shield generator
• Kewu Umppi'pa'-pattern citadel turret

History

A citadel is attacked by the Banished.

Covenant citadels were employed by the Covenant during several battles in 2531. One was employed during the Harvest campaign, in which it was used to defend the relic. Several were later used in the Battle for Arcadia; one was deployed in Pirth City to defend a Emp'seam-pattern Antlion that was shelling the city, while another was deployed in the city's outskirts. Several citadels and minibases were deployed under the protection of a massive Covenant dome, though they would eventually be destroyed by an Orbital bombardment. The Covenant also made extensive use of citadels during the Battle of Trove; UNSC forces from the UNSC Spirit of Fire destroyed four citadels to establish a stronger foothold on the surface.

At some point before the Battle of Line Installation 1-4 in 2552, Spartan-II Black Team destroyed a citadel. Shortly following the end of the Human-Covenant War, a citadel being used as an airbase on the swamp-moon of Kostroda by shipmaster Let 'Volir would be attacked by Atriox and his Banished forces.

In-game information

Halo Wars

The citadel with no buildings or fortifications.

"Use this to construct a new Outpost Base. Eventually, it can be upgraded to a full Citadel, increasing your ability to crush the evil enemy filth."

— In-game description

In Halo Wars, a default Outpost costs 500 resources to be built, and only provides three construction slots and no turret foundations. A gravity lift is automatically placed at the front of the base; units (other than the Scarab) can be sent to the gravity lift which transports them to the Leader unit's location. The gravity lift can also be used to recall the Leader unit to the base instantaneously for the cost of 100.

The Outpost has two upgrades, Keep and Citadel.

• The Keep is an upgraded version of the Firebase, retaining the command center, but adding two more building sites (for a total of five) and four turret foundations.
• The Citadel upgrade allows two other building sites, totaling to seven building sites and the same four turret sites from the station. It also features a self-destruct sequence allowing it to destroy itself for other allies to make a base in its spot and damage any enemy units nearby. The Citadel also allows for a lock sequence that will not allow any newly trained units to leave the base when done training/being produced.

Each building slot and turret slot can accommodate one additional structure.

Name	Type	Cost			Description
		Population	Tech	Resources
Gravity Lift	Teleport Units to Leader	N/A (Free; built with the Citadel)			N/A
Turret	Base Defense	N/A	0	250	Turrets are good at defending bases against all enemy targets.
Warehouse	Produces Resources	N/A	0	100	The Covenant Warehouse produces the resources needed to train units, building buildings, and buy technology upgrades. Bases that have great economic production might have 6 Warehouses.
Temple	Increases Tech Level	1/1	0	500	Temples allow the Covenant to access advanced buildings, units and technology upgrades.
Shield Generator	Base Protection	N/A	1	200	Generates a large bubble shield to protect the base. Multiple Shield Generators can be built in a base to compound the shield's strength.
Hall	Trains Infantry	N/A	0	150	The Covenant Hall rallies infantry units to the cause. Upgrades for infantry units are also housed here.
Factory	Trains Vehicles	N/A	0	150	Most Covenant vehicles are pieced together and upgraded at the Factory.
Summit	Trains Aircraft	N/A	0	150	Covenant aircraft are constructed at the Summit. Aircraft upgrades are also in this structure.

Among other things, the Citadels themselves can produce units and corresponding improvements for them.

Name	Type	Cost			Description
		Population	Tech	Resources
All Leaders
Keep	Upgrade	N/A	0	300	Upgrades base to a Keep, which adds two more building sites.
Citadel	Upgrade	N/A	0	400	Upgrades base to a Citadel, which adds two more building sites.
Scarab	Uber Unit	20	3	3,000	The Covenant Super Unit. These massive assault vehicles have a devastating beam that can tear part virtually anything.
Arbiter
Suicide Grunts	Special Forces	1	1	160	Suicide Grunts are a perverted variant of the already dangerous Grunts. They can sacrifice themselves on enemy targets using the Suicide Ability.
Zeal	Upgrade	N/A	2	500	Suicide Grunts are faster in Suicide Mode.
Defile	Upgrade	N/A	3	800	The Suicide Grunt's explosion splashes enemies with burning chemicals.
Brute Chieftain
Brute	Special Forces	1	1	150	Specialized, heavy infantry with powerful Brute guns, these squads dish out lots of damage.
Jump Pack Ability	Upgrade	N/A	2	500	Enables the Jump Pack Ability, allowing Brutes to quickly cross the battlefield.
Electric Shot	Upgrade	N/A	3	800	The Bute Shot causes electrical stun damage when it hits.
Prophet of Regret
Elite Honor Guard	Special Forces	1	1	125	Specialty troops that guard the Prophet. These stealthy infantry wield powerful plasma swords capable of shredding any target.
Cloak Ability	Upgrade	N/A	2	500	Enables Cloak Ability.
Personal Shield	Upgrade	N/A	3	800	Adds a personal shield that decreases incoming damage.

Gallery

Browse more images in this article's gallery page.

Concept art and illustrations

• 

  Concept art of a building for the Citadel.

• 

  Concept art of the gravity lift pad on the front of the citadel.

• 

  Concept art of the Covenant citadel.

• 

  An early 3D placement pass on a Citadel in Halo: Rise of Atriox.

• 

  Early sketch of the Citadel in Halo: Rise of Atriox.

Renders

• 

  The citadel's turrets, building pad, and gravity lift.

• 

  A render of the citadel model in Halo Wars, with poly and texture information.

• 

  A render of the Covenant minibase with no attached buildings.

Screenshots

• 

  A shielded Covenant citadel.

• 

  A Covenant citadel defended by Covenant troops and vehicles.

• 

  A Covenant citadel under attack.

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  A Citadel and a Covenant army supporting it.

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  Two Citadels on Frozen Valley.

• 

  A Citadel in a round of Tug of War on Pirth Outskirts.

List of appearances

• Halo Wars (First appearance)
• Halo: Blood Line
• Halo Wars 2 (Mentioned only)
• Halo: Rise of Atriox