Halo Alpha
Halo Alpha


Pillar of Autumn redirects here. For other uses, see Pillar of Autumn (disambiguation).
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There was only one ship.
One? Are you sure?
Yes. They called it the Pillar of Autumn.

UNSC Pillar of Autumn (HCS: C-709)[8][9] was a Halcyon-class light cruiser in the UNSC Navy. It was informally referred to as the Autumn, and its name abbreviated to "PoA." The motto for the ship was Ad Arcendam Hostium.[6]

Prior to the Fall of Reach, Pillar of Autumn was selected to support Operation: RED FLAG, a SPARTAN-II operation to capture Covenant leaders. Captain Jacob Keyes was placed in command. The operation was forestalled by the Covenant assault on Reach and the cruiser was one of the few UNSC survivors and fled the system having lost most of its intended SPARTAN-II passengers.

The cruiser was guided to the Soell system by the AI Cortana. There it was engaged by a Covenant fleet guarding Installation 04. Keyes crash-landed the ship on the installation where the surviving crew continued the battle against the Covenant and later, the Flood. The ship's sole remaining combat effective SPARTAN-II, John-117, was forced to detonate the crashed Pillar of Autumn's fusion reactor, destroying the ship and the installation to purge the Flood without firing the said installation's defenses.

The Pillar of Autumn had a few sister ships, including the UNSC Dawn Under Heaven and the UNSC Toulouse.[10] It also inspired the creation of its successor, the Autumn-class heavy cruiser.

Operational History[]

PoA logo

The Pillar of Autumn's ship emblem.


The Pillar of Autumn was originally designed by Dr. Robert McLees.[4] The keel was laid in 2507.[6] It was constructed at the Reyes-McLees Shipyards on Mars in 2509 as one of the then-new Halcyon-class cruisers.[1] The ship was launched on December 1, 2510.[4] Due to its expensive honeycomb structure, the blueprints of the Halcyon-class were radically altered soon after the Autumn's construction with only the first eleven of fifty possessing it.[11]

Human-Covenant war[]

It saw action during the First Battle of Arcadia against the Covenant in February 2531. The cruiser was heavily damaged engaging two CCS-class battlecruisers.[12] The cruiser contributed experimental M-145D Rhino to the ground fighting.[13]

The cruiser was later decommissioned with the other Halcyon-class cruisers. Unlike its sisters in Aszod, the Autumn was merely placed in long-term storage as military surplus, just in case it should be needed later. As fate had it, that time came in 2550 when the UNSC was desperately low on ships to defend the Theater of Operations around Zeta Doradus (the site of secret ONI projects), and it was reactivated as an emergency support ship.[11]

Preparations for Operation: RED FLAG[]

Main article: Operation: RED FLAG

By 2552, it was obvious to the UNSC that the war could not be ended with conventional military action. A desperate plan had been conceived to end the war by capturing the Covenant's leadership and forcing the enemy to the negotiating table. SPARTAN-II commandos would commandeer a disabled Covenant ship, locate the Covenant homeworld and abduct the targets. Pillar of Autumn was selected on August 25 by the AI Cortana to disable an enemy ship and deliver the Spartans aboard; the ship was selected for the Halcyon-class's durability, despite its class's usual lack-luster offensive capabilities.[14] Command of the ship was given to Jacob Keyes, a well-proven tactician and Captain.

The cruiser received a refit for the mission, adding a variety of upgrades including a state-of-the-art fusion power plant.[15] The refit was lead by Senior Engineer Adam Crockett.[4] Cortana was transferred to handle the shakedown.

Also on board was a D77-TC Pelican that had been modified for the SPARTANs selected for the mission. It had double the armor plating, grappling attachments, and a serrated titanium ram.

Fall of Reach[]

Main article: Fall of Reach

Pillar of Autumn pushes through the Covenant blockade and escapes Reach.

On August 29, R7 thrust couplings were installed to the ship. The Autumn was prepared to deploy on August 30, though it was stuck in heavy traffic in orbit over Lábatlan, Reach.[16] Before it could depart the Epsilon Eridani System it was recalled to Reach; the UNSC fleet was mustering in preparation for an imminent Covenant attack on the planet. Cortana remained in control as the ship's normally assigned AI was not yet operational.

The UNSC hoped that an opportunity to capture an enemy ship would present itself, however the course of the battle forced the Spartans to deploy on other missions. Blue Team was deployed in the modified Pelican to Reach Station Gamma, in order to enact Cole Protocol on the UNSC Circumference. Unfortunately, the modified Pelican was destroyed when it crashed into the station.[citation needed] Red Team went planet side to reinforce the Orbital Defense Generators.

During the space battle over Reach, Pillar of Autumn defeated a Covenant supercruiser on its own that even the Fleet's carriers could not defeat, proving Pillar of Autumn to be one of the most durable warships ever built by UNSC Navy. While the cruiser performed well, the battle was lost as the Orbital Defense Platforms fell silent. There was only time to recover the remnants of Blue Team, John-117 and the clinically dead Linda-058, before the ship was forced to flee the system.

At some point during the conflict, Pillar of Autumn returned to drydock at the Aszod ship-breaking facility to rescue any survivors on the planet and retrieve a package. Shortly before the ship fled the system, the remnants of Noble Team were tasked with delivering a fragment of Cortana's data chip to Pillar of Autumn. The ship left drydock immediately afterward. It was nearly destroyed by a CCS-class battlecruiser before it could take off, but the Cruiser was destroyed by Noble Six with an Onager.[17]

Pillar of Autumn was supposed to have made a random Slipspace jump in accordance with the Cole Protocol. However, Cortana surreptitiously guided the ship to the Soell system and, ultimately, to Installation 04 instead. The AI used coordinates obtained from a Forerunner artifact on Sigma Octanus IV.[18] The Covenant pursued along the cruiser's exit vector and arrived at Soell first with a battle group of CCS-class battlecruisers.

The Battle of Installation 04[]

Main article: Battle of Installation 04

Pillar of Autumn taking plasma impacts at the Battle of Installation 04.

Pillar of Autumn was immediately engaged upon arriving at Threshold. The cruiser was spared destruction by the Prophet of Stewardship who feared stray Plasma Torpedo fire might damage Installation 04. So the Covenant made to board and capture the ship instead. Pillar of Autumn destroyed four ships and damaged Truth and Reconciliation before boarders disabled its Magnetic Accelerator Cannon with an Antimatter charge.

Captain Keyes ordered the crew to abandon ship. John-117 was given Cortana for safekeeping, and ordered to keep the AI out of enemy hands as part of the Cole Protocol.[2] The crew left the ship for the ring in whatever craft were available and the cryo pods were jettisoned, though the Covenant also actively both tried to board the Pillar just after personnel were jettisoned, while also seeking to destroy the lifeboats to prevent them from escaping the ship and landing on the ring; Keyes directed Pillar of Autumn on a course to crash land on the ring manually. The Covenant finally began hitting the ship with plasma torpedoes, but the cruiser survived the landing reasonably intact. The survivors would later transfer supplies from the ship to Alpha Base.

The release of the Flood added an unexpected dimension to the battle. Monitor 343 Guilty Spark was preparing to fire the installation in response to the outbreak; in conjunction with the entire Halo Array this would wipe out all sentient life in the galaxy.[19]


John-117 and Cortana returned to Pillar of Autumn, finding the ship full with Flood and Covenant forces, to destroy the ring by detonating the still-functioning fusion reactors just after getting their hands on Keyes' neural implants for authorization. An attempt to activate the cruiser's self-destruct sequence from the bridge failed due to 343 Guilty Spark's interference, forcing the Spartan to manually destabilize the reactors with tactical ordnance.[20]

Halo Reach Combat Evolved Ring

Pillar of Autumn flying towards Installation 04.

The Spartan and AI escaped the subsequent detonation and the ring aboard a Longsword fighter still docked in Launch Bay 7. The effort to destroy Halo with Pillar of Autumn succeeded, sparing the galaxy from the Flood and a Halo activation. Of the ship's crew, only the chief and a Pelican with four more survivors, including Sergeant Johnson, survived the Ring's destruction.[20]


Pillar of Autumn would be so well known that it would have a line of cruisers that entered service after the Human-Covenant war, the Autumn-class heavy cruiser, named after it and the lead ship of the class, UNSC Pillar of Autumn II, in honor of the original Pillar of Autumn.

Also, the Autumn's success made than, following the war, the hulls of other Halcyon-class ships were reworked to become the first ships in a new class of Cruiser: the Autumn-class heavy cruiser.[21]



Pillar of Autumn was roughly 43 years old at the time of its escape from Reach and its later destruction on Installation 04. It was a cruiser of the Halcyon-class, the third largest in the UNSC Fleet at the time.[1] Like other Halcyon ships, Pillar of Autumn was equipped with a honeycombed internal bracing structure that allowed it to function even after sustaining critical levels of damage.

Power Plant[]

PoA Reach

The refit Pillar of Autumn.

Prior to being refit for the Spartan mission, Pillar of Autumn was equipped with Mark II fusion engines (which supplied only 10% the power of modern reactors).[1]

Pillar of Autumn was refitted with an improved nuclear fusion engine that supported the two smaller existing reactors around a newer larger one, which were capable of boosting the overall power output by 300% for a short time if needed.

Fusion reactors generate extreme heat which must be removed in order for them to remain active without overheating. The Autumn's overhauled reactors were an especially severe case of this. Usually, the excess heat was conducted to a chemical agent which would then vent into space. However, Pillar of Autumn's upgraded specifications also included an upgraded cooling system, which featured a "laser-induced optical slurry of ions chilled to near-absolute zero," which is far more efficient than the typical method and removed the reliance on expendable chemical temperature-control substances. In essence, the amount of excess heat removed by the new system increased as the reactors' output did. This self-regulating and self-cooling power plant was critical in combat since it virtually eliminated a commander's concerns about overheating and slagging a ship's engines.

Due to the heavy reliance on reliable cooling, any disruption or damage to the cooling system could result in severe damage to the ships engines. This happened in the Battle of Installation 04, wherein the Master Chief (a.k.a John 117) was able to access the cooling system and disable the magnetic containment fields surrounding the engine core using explosives. Once these were destroyed, the reactor underwent a runaway reaction, resulting in temperatures of over 100,000,000 degrees and a thermonuclear explosion large enough to tear apart the Halo Installation.[20] This desperate last-resort strategy has been employed by the UNSC on a number of occasions, including after the events of Installation 04.


Initially the Autumn had just one regular MAC gun and six Archer missile pods.[1] The upgraded Pillar of Autumn received extensive refits, including several to its weapons systems. Eventually, it was host to a very powerful armament; far in excess of the original Halcyon-class ships.

  • One Mark II, Light Coil - 56A2D4/MAC.[3] The MAC gun fired lighter projectiles compared to most ship grade MACs, but these rounds worked much like Shredder Rounds. Each charge was able to fire 3 rounds. With extra power capacitors and power recycling systems, Pillar of Autumn's MAC gun could fire three consecutive shots per charge.
  • 32 M58 Archer Missile Pods.[4][Note 1]
  • One Shiva-class Nuclear Missile, loaded onto a remote-controlled Longsword interceptor.[5]
  • Three ship-launched HAVOK Tactical Nuclear Warheads.[5]
  • 18 M910 Point-defense guns[4] with overlapping fields of fire for point defense against single ships. Two of these cannons were later salvaged by the surviving humans on Installation 04 and were used to defend Alpha Base.
  • Six M66 Sentry autocannon turrets[4]
  • Eight Mark 33 Spitfire coilgun batteries[4]


Engine Room[]

Pillar of Autumn's engine room was a large, three-deck high chamber allowing access to the fusion engine core. Side passages allowed for movement from the bottom deck all the way up to the catwalks on the third. The manifolds into the cores were suspended above the second deck. Controls on the third deck retracted these manifolds, exposing a vent that led directly into the core. It was using this method to expose the core via the vents that John-117 ultimately destroyed the ship and Installation 04. This room is the largest room in Pillar of Autumn with the exception of the hangar bay and the "Leap of Faith" room.[20]


Airlock 31, 32: Lifeboat destroyed by the Covenant to make way for a Boarding Craft.
Airlock 51: Lifeboat was destroyed by unseen Covenant artillery as it departed from the airlock.
Airlock 52, 53, 61, 62, 63: Lifeboats managed to make it out of the vessel.1

1Airlock 61: John-117, Cortana, nine other Marines on board and the Bumblebee pilot.


The complement of the Autumn was quite extensive. In terms of infantry, there were 800 Marines and 400 ODSTs.[4]

A number of vehicles were also carried by the Autumn including five Longsword Interceptors, 12 Pelican Dropships, two D96-TCE Albatross, 20 Scorpion Tanks, and 60 Warthogs. The ship also had 216 SOEIVs[4] The ship also carried several UH-144 Falcons.[22] There were also more than 63 Lifepods.

During the Battle of Arcadia, the Autumn also carried over nine Rhinos.[13]

Known Complement[]







Known Crew[]

Naval Crew


  • Jonesey (Unknown crew member's cat)



The bulletin board.

  • Pillar of Autumn's model is approximately 1.17 km long, a reference to John-117.[23] The ship's length is exaggerated in the final level of Halo: Combat Evolved to provide a 3 km vehicular course.
  • The Marathon logo is prominently displayed on Pillar of Autumn's starboard and port sides in Halo: Combat Evolved. The ship's official emblem has the Marathon logo as well. The Marathon logo was also visible in the window of the ship in the opening cut scene of the level The Maw. However, the ship's official emblem was changed to the Seventh Column logo in Halo: Reach and Halo: Combat Evolved Anniversary, as seen on the hull of Pillar of Autumn and Captain Keyes' ID Patch to avoid property rights issues.
  • On the first level of Halo: Combat Evolved, the bulletin board just outside the bridge of the ship contains 7 amusing clips, including some throwbacks to Marathon and a flier for a missing cat called Jonesey, a reference to the cat from the Alien movies. The board also has a flier telling Marines to "Keep it Clean", a statement later used in Halo 3: ODST.
    • The re-textured bulletin board in Halo: Combat Evolved Anniversary includes a classic Internet gag image of a "cat found" poster mistaking an opossum for a cat, a poster labelled "Dark Planetoid Rising" featuring the Forerunner planet Requiem as it appeared in the Legendary ending of Halo 3 and a "troll" face on the bottom-left. The board also includes an image of a goose with the caption "Have you seen my Goose," the "Fist of the Unicorn" band, and others.
  • In Halo: Fall of Reach, Pillar of Autumn is described as having a command chair and a rotating section to simulate gravity. In Halo: Combat Evolved, both of these are absent.
  • Spartan Nicole-458 in Dead or Alive 4 has a combo move called "the Pillar of Autumn".
  • Pillar of Autumn is the first UNSC ship in all the Halo games that you are able to explore the inside of.
  • In the beginning shots of The Mona Lisa episode 5, the first part of the ship name, "The Pillar of Au," can be seen floating in space.
  • In Halo: Combat Evolved, the antennas are positioned on the first hexagonal structure. In Halo: Reach, they are positioned on the second and a defense cannon is positioned in the first hexagonal structure.
  • In the last campaign level of Halo: Reach, The Pillar of Autumn, if the player does not destroy the battlecruiser at the end, the final cutscene will show Pillar of Autumn being cut in half by a glassing beam.
  • Although the crew of Pillar of Autumn were widely credited with being the first humans to encounter the Flood, the crew of UNSC Spirit of Fire encountered the Flood decades earlier.
  • Despite the ship's pristine appearance in Halo: Combat Evolved (Anniversary) and Halo: Reach, Pillar of Autumn was damaged during the Fall of Reach.
  • This is the most featured named ship in the Halo universe.


Concept Art[]

Renders & Size Comparisons[]

Exterior Shots[]

Interior Shots[]




  1. In Halo: The Fall of Reach, pages 274-275 Captain Keyes mentions performing a fly-by inspection of the starboard shuttle bay and counting Archer Missile Pods thirty across and ten down, making for 300 Archer Missile Pods. The next sentence then reads "Each pod held dozens of missiles."


  1. 1.0 1.1 1.2 1.3 1.4 Halo: The Fall of Reach, Page 238 ("The Pillar of Autumn is forty-three years old," Cortana said. "Halcyon-class ships were the smallest vessel ever to receive the cruiser designation. It is approximately one-third the tonnage of the Marathon-class heavy cruiser currently in service.")
  2. 2.0 2.1 Halo: Combat Evolved - Level: The Pillar of Autumn
  3. 3.0 3.1 3.2 3.3 Halo Waypoint - Universe - UNSC Pillar of Autumn
  4. 4.00 4.01 4.02 4.03 4.04 4.05 4.06 4.07 4.08 4.09 4.10 4.11 4.12 4.13 4.14 4.15 4.16 Halo: Warfleet – An Illustrated Guide to the Spacecraft of Halo, Page 24 & 25
  5. 5.0 5.1 5.2 5.3 Halo: The Fall of Reach - Chapter 29, Page 275 ("In response to Captain Keyes' question about the small single ships in the launch bay, Lieutenant Hikowa states, "Yes Sir. One of the Longswords is equipped with a Shiva Nuclear Warhead; it can be remote piloted. We also have three HAVOC Warheads on board")
  6. 6.0 6.1 6.2 Halo Mythos: A Guide to the Story of Halo, Page 95
  7. Halo 2 - Level: The Heretic
  8. Halo: Combat Evolved: Sybex Official Strategies & Secrets, Page 60
  9. Bungie.net - Bungie Weekly Update 01.29.10
  10. Halo Waypoint - News, Rockin' & Railin'
  11. 11.0 11.1 Halo: Combat Evolved: Sybex Official Strategies & Secrets, Page 60
  12. Halo Wars - Level: Arcadia City
  13. 13.0 13.1 Halo Wars - Level: Dome of Light
  14. Halo: The Fall of Reach, Page ?? ("…At the time deemed unnecessarily over massed and costly due to series of cross-bracing and interstitial honeycombs… Halcyon-class ships, however, have a reputation for being virtually indestructible. Reports indicate these ships being operational even after sustaining breaches to all compartments and losing ninety percent of their armor.")
  15. Halo: The Fall of Reach, Page ??
  16. Halo Waypoint - Data Drop 6
  17. Halo: Reach - Level: The Pillar of Autumn
  18. Halo: The Fall of Reach - Epilogue, Page 336
  19. Halo: Combat Evolved - Level: Two Betrayals
  20. 20.0 20.1 20.2 20.3 Halo: Combat Evolved - Level: The Maw
  21. Halo: Warfleet – An Illustrated Guide to the Spacecraft of Halo - pages 26 & 27
  22. Halo: Fireteam Raven - Campaign
  23. halo.bungie.org - The Pillar of Autumn Conundrum