Halo Alpha
Halo Alpha

The Inner Colonies, sometimes referred to as the Core Worlds,[1][2] were the first extrasolar worlds to be heavily surveyed and developed. They were along low-energy slipspace routes.[3]


The Inner Colony Wars[]

Main article: Inner Colony Wars

It is known that there was a war some time before the 26th century called the "Inner Colony Wars."[4] Very little is known about it and it might just be an alternate name of the Interplanetary Wars, though the name would be of a post-Outer Colonies age, and probably only referring to the Sol system colonies.

Continuing Development[]

Halo 4 Majestic Map Pack Casbah 2

Casbah, the capital of the commercial powerhouse, Tribute.

Main article: Domus Diaspora

The Inner Colonies consisted of the 210 planets which were colonized before 2390.[5]

In 2490, Reach, which was located near the boundary of the Inner and Outer Colonies, became the UNSC's military center. As the UNSC began settling the Outer Colonies, the Inner Colonies, with their established social and economic infrastructures, became the political and economic basis of the UNSC, supplied with raw materials from the newer settlements.[5]

The Insurrection[]

Main article: Insurrection

While the outer colonies held the brunt of the Insurrection, the inner colonies were not spared violence. Tribute was turned into a battleground as a part of Operation: TREBUCHET[6] and Reach was the site of an attack on a luxury liner.[7]

The Human-Covenant war[]

Main article: Human-Covenant war

The war with the Covenant would take years to reach the inner colonies, mostly due in part to the Cole Protocol which was designed with the protection of Earth and the inner colonies in mind.[8]

As the Covenant rampaged through the outer colonies, refugees poured into the border system of Ectanus 45.[9]

The Siege of the Inner Colonies[]

Main article: Siege of the Inner Colonies

In 2536 the Covenant breached into the inner colonies,[5] despite the utmost diligence to the Cole Protocol.

As the years went on, many colonies were attacked and some were glassed, like Skopje.[10] Some battles, like the Battle of Ballast, were even won by the UNSC.[11] However, the odds were getting worse every year and in the July of 2552, Reach was discovered.[12] The resulting battle would see the planet ultimately glassed,[13][14] but would pave the way for the very significant Battle of Installation 04.[15]

H2A Cutscene BattleofEarth

The Battle on Earth rages on.

After almost 27 years of war, Earth and the Sol system were attacked. Earth's New Mombasa would get the first hit.[16] Mars would also come under assault, a battle the UNSC lost.[17] Earth would continue to be fought over up until December 2552, when the portal to the Ark was discovered.[18] This led to final battle of the war, the Battle of Installation 00.[19]


Immediately following the war, rebuilding the colonies was the biggest priority. Earth began rebuilding in January 2553,[20] and in November, Reach was scouted for possible reterraforming.[21]

New Phoenix Incident[]

Main article: New Phoenix Incident

In the July 2557, the Ur-Didact's ship, Mantle's Approach, arrived in Earth's orbit. The Didact would fire the Composer at the city of New Phoenix.[22] The city was left in quarantine for eight months.[23]

Inner-Outer Colony Disconnect[]

Following Benjamin Giraud's interruption of a joint UEG Senate and ONI meeting, the Waypoint buoys connecting the inner and outer colonies were shut down.[24] When Benjamin was publicly discredited on ECB, tensions died down and the buoys were turned back on.[25]


Main article: The Reclamation

In 2558, Cortana sent her Guardians to Earth, and most likely other Inner Colonies.[26]




Transit in the Inner Colonies is monitored by the Inner Territories Transportation Administration.[27]


While the CMA operated in both the Inner and Outer Colonies, by 2400, the UNSC's FLEETCOM and UNICOM operated along side them in the Inner colonies. Sometime after that, the CMA chose to monitor only the Outer Colonies. Thus the UNSC became the sole defender of the Inner Colonies.[28]

By the 26th century, the defenses of the Inner Colonies were known to be incredibly strong. On the edge of the Inner Colonies is Fort York, which housed the best and brightest soldiers.[29] The Sabre Program was also designed with the defense of the Inner Colonies in mind. In fact, several Inner Colony worlds held launching stations for them.[30]


Much of the astrography of the Inner Colonies isn't known. It is known that the border worlds of Inner Colonies are in the Outer Fringes.[31] There is also one known FLEETCOM sector within the Inner Colonies, Sector One.[32]

Known Colonies[]

There are at least 210 Inner Colonies.[5] So far, only 20 colonies and 3 systems have been referenced.

System Colony Status
Ectanus 45 system Chi Rho Attacked during the war, unknown overall status.
Eiro Sparsely populated.
Epsilon Eridani system Reach Glassed in 2552, terraformed to be habitable by 2589.
Tribute Glassed in 2552
Tantalus Unknown, likely glassed
Circumstance Unknown, likely glassed.
Beta Gabriel Unknown, likely glassed.
Sol system Earth Still held
Luna Unknown, likely survived.
Mars Still held
Jovian Moons Unknown, likely survived.
Titan Unknown
Unknown Actium Glassed in May 2545
Ballast Unsuccessfully attacked
Camber Glassed
Gannick 22 Still held
Imber Attacked, unknown status
Minister Still held
Miridem Attacked, unknown status
New Carthage Still held
Skopje Glassed in 2547



  1. Halo: Contact Harvest - Page 33
  2. Halo Wars: Genesis
  3. Halo: Warfleet – An Illustrated Guide to the Spacecraft of Halo - Page 91
  4. Halo Graphic Novel, Second Sunrise over New Mombasa
  5. 5.0 5.1 5.2 5.3 Xbox.com: Halo Storyline (Defunct, Copy on HBO Forums and Wayback Machine)
  6. Halo: Contact Harvest - Pages 9-20
  7. Halo: Contact Harvest - Page 127
  8. Halo: The Fall of Reach - Page 135
  9. Halo: The Cole Protocol - Page 25
  10. Halo: Evolutions - Essential Tales of the Halo Universe - Dirt, Page 313
  11. Halo Encyclopedia - Page ??
  12. Halo: Reach - Level: Winter Contingency
  13. Halo 2 - Level: The Heretic
  14. Halo: Reach - Level: The Pillar of Autumn
  15. Halo: Combat Evolved - Level: The Pillar of Autumn
  16. Halo 2 - Level: Cairo Station
  17. Halo: Uprising Issue 1
  18. Halo 3 - Level: Tsavo Highway
  19. Halo 3 - Level: The Ark
  20. Halo: Glasslands - Page 27 (Electronic Version)
  21. Halo Waypoint: Catalog Interaction - Page 43
  22. Halo 4 - Level: Midnight
  23. Halo: Escalation Issue 7
  24. Hunt the Truth - Episode 09: Phantoms (Part 1)/(Part 2)
  25. Hunt the Truth - Episode 13: In The Bag (Part 1)/(Part 2)
  26. Halo 5: Guardians - Level: Guardians
  27. Hunt the Truth - Episode 05: Out of Time (Part 1)/(Part 2)
  28. Halo Encyclopedia - Page 69
  29. Halo: The Fall of Reach - Page 283 (Physical), Page 321 (Digital)
  30. Halo Waypoint (Xbox 360 App): The Universe - Vehicles - Sabre
  31. Halo: Cole Protocol - Page 22 (Electronic)
  32. Halo: The Fall of Reach - Page 289