Battle of Requiem

The Requiem campaign was a series of large scale battles and small skirmishes between the native inhabitants of Requiem, the Prometheans, and their subordinate allies and religious followers in the Covenant remnant against the intruding United Nations Space Command. These engagements marked the beginning of the Human-Promethean War on July 20th, 2557; the days following would see the conflict spread to Installation 03 and the human homeworld, Earth.

Background
In 2553, the aft section of the, carrying Spartan-II John-117 and AI Cortana, was transported via slipspace to the system Requiem was located after the Raid on Installation 04B. Cortana activated Forward Unto Dawn's emergency locator beacon while John-117 entered cryostasis. About one year later, Jul 'Mdama led his Covenant remnant to Requiem in search of the planet's "treasure". However, 'Mdama couldn't find a way into Requiem, and the fleet held its position outside of Requiem's opening. It would be 3 years later, in July 2557, when the Dawn was pulled towards the planet and 'Mdama's sent his forces to board the frigate to prevent the wreckage from approaching the planet. As the Covenant remnants entered the ship, Requiem began to scan the Dawn for a "Reclaimer".

Opening Skirmishes
Cortana awoke John-117 from cryostasis, and informed him of intruders on the Dawn. When the duo found out that there was a Covenant fleet around the Dawn and one of the s was moving into a intercept course, Cortana instructed John-117 to fire one of Dawn's missiles at the battlecruiser. John-117 battled through the wreckage and managed to destroy the cruiser moments before it fired its energy projector. During the attack, John-117, exposed to the Dawn outer hull, was scanned by Requiem, which proceeded to open its interior for the ships. The Dawn, along with several Covenant cruisers, were pulled into Requiem's interior.

John-117 survived the fall into Requiem's inner planet, and intended to hijack one of Covenant ships to return to Earth, where he would be able to find Doctor Catherine Halsey to assess Cortana's rampancy. However, had picked up Forward Unto Dawn's distress beacon, and was approaching the planet. In the middle of finding a way to locate the Infinity, John-117 and Cortana accidentally triggered Requiem's defense, the Prometheans. The Prometheans attacked the Spartan as well as the Covenant. In an effort the warn Infinity of Requiem's gravity well, John-117 and Cortana disabled two energy pylons inside Requiem's core in order to eliminate interference emitted from a satellite in the core. When John-117 attempted to contact Infinity in the satellite, it was revealed that the Didact had purposely manipulated Infinity signal to trick John-117 into releasing him from his Cryptum. The Didact openly declared war on humanity and gained control of the mechanized Prometheans as well as the Covenant remnant forces. John-117 escaped Requiem's core on a Ghost by driving through a portal just as the Infinity entered Requiem.

Arrival of the Infinity
The UNSC Infinity crashed into a jungle in Requiem, and was immediately under attack from the Prometheans and Covenant forces. Infinity 's commanding officer, Captain Andrew Del Rio, deployed UNSC forces for reconnaissance, believing that the Infinity would be able to fend off her attackers while providing support for ground forces. The ill-prepared UNSC Marines were overwhelmed by the unfamiliar Promethean forces and suffered heavy casualties. In addition to losing landing zones, many Pelican dropships were shot down. Infinity was invaded by the Covenant remnant and Prometheans, and the Didact was extracting information from the ship's mainframe. John-117 joined Thomas Lasky and Sarah Palmer just as Captain Del Rio recalled ground forces to return to Infinity. John-117 cleared a landing zone for the UNSC forces and headed to Infinity 's crash site. There, John-117 and Spartan-IVs led an assault force to Infinity 's hangar bay, which was occupied by Covenant remnant and Promethean forces. John-117 piloted a Mantis and fought through Infinity 's maintenance corridor to one of Infinity 's weapon systems. After John-117 destroyed the Covenant jammers near Infinity 's weapon systems, the Infinity was able to disable two s and damage the Didact's Cryptum, prompting the Didact to retreat. The repaired Infinity left her crash site, but since she was still under the effect of the Requiem's gravity well, Captain Del Rio sent John-117 and Gypsy Company to take down the Forerunner anti-air particle cannons near the gravity well.

Assault on the Gravity Well
Gypsy Company, onboard a Mammoth and led by Commander Thomas Lasky, destroys the first and second anti-air particle cannons. However, a Covenant Lich managed to heavily damage the Mammoth. Even though John-117 destroyed the Lich, the Mammoth was forced to stop when it approaches a Forerunner structure.

John-117 entered the Forerunner structure, and, with the help of AI Cortana, disabled the last two Forerunner anti-air cannons. John-117, investigating the sudden disappearance of Cortana in the Forerunner structure, was taken to an archived personality of the Librarian. The Librarian informed John-117 of the Didact's plan to imprison humanity into digital form with the Composer, and altered John-117's genes, an action that would prove itself useful when the Didact's forces raided Ivanoff Station. John-117 returned to a UNSC convoy led by Master Sergeant Marcus Stacker, and eventually reached Requiem's gravity well. There, the Infinity, under the guidance of John-117's Target locator, destroyed the gravity well.

List of appearances

 * The Commissioning
 * Halo 4