Battle of Circinius IV

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Battle of Biko, Operation: SILENT STORM


Battle of Mesra

Battle of Circinius IV
CirciniusIV attacked1.jpg


Human-Covenant War


April 26, 2526[1]


Circinius IV, Circinius system


Covenant victory

  • Almost all UNSC personnel and civilians killed
  • Corbulo Academy and Circinius IV glassed
  • Spartan Blue Team successfully retrieves three survivors

United Nations Space Command


  • Near-total annihilation of Corbulo Academy's cadet corps and staff
  • Entire Marine garrison and ODST response force
  • Near-total annihilation of the population of Circinius IV
  • At least one Sangheili
  • Several Kig-Yar
  • At least two Mgalekgolo

John-117: "You're the only survivors."
Michael Sullivan: "In the school?"
John-117: "On the planet."
— John-117 notifying the cadets of the planet's near-total fatalities.

The Battle of Circinius IV was an engagement between UNSC and Covenant forces on the colony of Circinius IV in mid-2526. It was not only one of the first battles of the Human-Covenant War, but also one of the first deployments of Spartan-IIs.[2]


After the first engagements on Harvest, ONI Section II kept the Covenant invasion secret from the general population. This encompassed the denizens of Circinius IV (including the staff and cadets of the Corbulo Academy of Military Science) in what was likely the first application of the recently introduced WINTER CONTINGENCY. However, the academy's superintendent, General 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. Unfortunately, these preparations would prove ineffective against the Covenant.


On April 26, 2526, the Covenant launched a surprise attack on Circinius IV. Three Ceudar-pattern heavy corvettes entered the atmosphere and attacked Corbulo Academy. Locally stationed Marines provided an initial defense of the academy and the evacuation of the cadets via the school's space elevator was begun immediately. Orbiting UNSC vessels soon deployed Orbital Drop Shock Troopers directly onto the campus. However, one of the Covenant corvettes fired on the elevator, causing it to collapse on the school and halt the evacuation. Since all the cadets and staff had converged near the elevator for evacuation, the collapse of the elevator killed many members of the academy. Moments later, the survivors came under attack by Sangheili and Kig-Yar troops.[2]

Corbulo's officer cadets were caught off-guard by this attack. General Black was killed within minutes of the attack; Colonel K.L. Mehaffey attempted to organize the surviving cadets inside the tunnels, though she too was quickly killed. Covenant forces soon overwhelmed the ODSTs and Marines, and proceeded to annihilate the planet's entire population, with only four Cadets April Orenski, Thomas Lasky, Chyler Silva, and Michael Sullivan left alive. SPARTAN-II Blue Team were then subsequently deployed in response to the cadets' distress beacon. Spartan John-117 infiltrated the besieged school and arrived just in time to rescue the surviving cadets from a Sangheili Zealot. After contacting Kelly-087 and arranging for a Pelican extraction, John-117 broke open the cadets' weapons lockers and allowed the cadets to arm themselves.[3]

The Spartan led the survivors to the academy's exterior, where they were ambushed by Kig-Yar Snipers. Cadet Sullivan was wounded during the firefight, but survived. After dispatching the snipers, they retreated from the combat zone in General Black's personal Warthog.[3] During the drive, however, they came under heavy fire from more Kig-Yar and were eventually forced to abandon their vehicle. Silva was killed by a needler round, and the rest of the group was attacked by a pair of Mgalekgolo. John-117 depleted all his ammunition killing one of the Mgalekgolo, leaving him with only a single grenade. He decided to take on the remaining Mgalekgolo alone, buying the surviving cadets time to escape. However, Cadet Lasky volunteered to distract the alien while John-117 got into position. Lasky successfully drew the Mgalekgolo's fire, allowing John to plant the grenade under its armor. The resulting detonation blew the Mgalekgolo to pieces.

As morning arrived, the survivors reached Blue Team's Pelican just as the Covenant began glassing the planet. Impressed by Lasky's actions, John-117 gave him a fragment of the Mgalekgolo's armor.[4]


Presumably following the battle, Marines (including Edward Buck) conducted Operation: ABLE SENTRY, a force reconnaissance mission that paved the way for Operation: PHALANX.[5] The exact nature and chronology of these operations are unknown, but likely couldn't have occurred prior to the Covenant's surprise attack.

While the academy and virtually the entire planet's population were wiped out, the battle would have a lasting impact on Thomas Lasky, who, inspired by John-117, decided to stay in the UNSC, eventually rising to the rank of Commander within the Navy. Following the war's end, Lasky became the executive officer of the UNSC Infinity. In 2557, 31 years after Lasky first met John-117, he would be reunited with the SPARTAN on the Forerunner shield world known as Requiem. Once again, they would work together, this time to save Earth from the Didact during which time Lasky achieved the rank of Captain and was given command of the Infinity after Fleet Command was displeased with Andrew Del Rio's decision to abandon the Master Chief on Requiem as opposed to Lasky helping him.[6]


A Spartan-IV NPC at the beginning of the Halo 4 campaign level Shutdown may occasionally refer to the Circinius IV conflict. He claims that the anniversary of the battle occurred "just last week", despite the level being set in late July.[7] While this is likely to be a simple oversight, it is possible that the battle for the planet was prolonged due to a UNSC reprisal (much like the extended campaign to reclaim Harvest) and continued well into July.


List of appearances[edit]


  1. ^ Halo Waypoint Forums - Today in Halo
  2. ^ a b Halo 4: Forward Unto Dawn, Part 3
  3. ^ a b Halo 4: Forward Unto Dawn, Part 4
  4. ^ Halo 4: Forward Unto Dawn, Part 5
  5. ^ Halo 5: Guardians Limited Edition, Spartan Locke's Classified Orders
  6. ^ Halo 4, level Midnight
  7. ^ YouTube - Halo 4: Shit Marines Say