Circinius IV

From Halopedia, the Halo wiki

Circinius IV
CAMS - afar.jpg


Circinius system[1]

Orbital position:

Fourth planet


At least three[2]






Human (Non-native)




Unified Earth Government


Circinius IV[Note 1] was a Unified Earth Government Outer colony world in the Circinius system.[1][Note 2] The planet was orbited by at least three natural satellites. It was the location of the Corbulo Academy of Military Science, an officer training school for the offspring of high-ranking UNSC officials.[2] The space elevator located at Corbulo Academy was considered one of the planet's most spectacular sites.[3]


Topography and climate[edit]

Circinius IV features dense forests and mountains as well as large bodies of water.[2]



Human-Covenant war[edit]

Main article: Battle of Circinius IV

After the first engagements on Harvest, ONI Section II kept the Covenant invasion secret from the general population. However, Corbulo Academy's superintendent, General Daniel Black, was informed. As preparation for a possible attack, Black discreetly increased the readiness of the UNSC Marine garrison posted in the academy and authorized limited communications blackouts under the guise of routine maintenance procedures.[2]

The colony and the academy were attacked by the Covenant during the earliest days of the Human-Covenant War on April 26, 2526.[4] Orbiting UNSC vessels soon deployed Orbital Drop Shock Troopers directly onto Corbulo Academy's campus. The planet's space elevator was also destroyed, killing many of the escaping cadets as it fell.[5] During the battle, the Covenant killed almost the entire population of the planet. Only four cadets from Corbulo Academy survived the initial assault,[6] although one of them, Chyler Silva, died during the battle. Later, the planet was glassed by the Covenant.[7]

At some point following the planet's invasion, the UNSC launched Operation: ABLE SENTRY on Circinius IV to investigate Covenant activity on the planet. Edward Buck participated in this operation. Directly afterwards, Operation: PHALANX was initiated and carried out by UNSC personnel, including John-117, to rescue civilians on Circinius IV and to investigate Covenant invasion patterns.[8][9]

Production notes[edit]

Along with Hat Yai, Circinius IV is not mentioned in the Assembly's report on glassed worlds (dated January 1, 2530) in data pad 14 from Halo: Reach. From a real-world perspective, the obvious explanation is that the planet was created after the game's release, there is no clear in-universe reason for this omission. However, given that both worlds had some form of human population on their surface following their presumed glassing dates,[9] it is possible that both Circinius IV and Hat Yai were not entirely glassed by the Covenant.


List of appearances[edit]


  1. ^ Official material from 343 Industries consistently renders the planet's name as "Circinius-IV". The same naming scheme is used for Draetheus V from Halo: Spartan Assault. However, Halopedia omits the hyphen for the sake of convenience and for consistency with other planetary designations (e.g. Jericho VII and Draco III).
  2. ^ Only the Outer Colonies were attacked pre-2536.


  1. ^ a b c Halo Encyclopedia (2022 edition), page 50
  2. ^ a b c d Halo 4: Forward Unto Dawn, Part 1
  3. ^ YouTube: Halo Channel Premiere
  4. ^ Halo Waypoint Forums - Today in Halo
  5. ^ Halo 4: Forward Unto Dawn, Episode 3
  6. ^ Halo 4: Forward Unto Dawn, Episode 4
  7. ^ Halo 4: Forward Unto Dawn, Episode 5
  8. ^ Halo 5: Guardians Limited Edition, Dossier files - Edward Buck
  9. ^ a b Halo 5: Guardians Limited Edition, Dossier files - John-117