Human-Covenant War

Overview

The Covenant-Human War was fought from the year 2525 to the year 2553 and this is one of the primary stages for the Halo franchise. The war was primarily between the Covenant Empire, a vast religious 'brotherhood' of aliens; and the UNSC forces that were based primarily on Earth and had a number of adjoining colonies. During the later stages of the war, the terrifying Flood are introduced to the conflict and they are hostile to Human and Covenant alike. Later yet, there is a rift in the covenant after the Great Schism which sees two new factions forming out of the Covenant; the Loyalists, who are led by the Brutes, and the Separatists, who are led by the Elites and reluctantly ally to their one time foe the humans.

The basic premise of the War is that the Covenant (led by the Prophets) are collecting "artifacts" from the long dead Forerunners and seek to follow in their footsteps by undertaking the "Great Journey", essentially a pilgrimage to the afterlife. Due to a chance encounter, the Covenant forces meet a human frigate around the Harvest colony and a skirmish breaks out. The Prophets decree humanity as an affront to their gods, thus, beginning the most destructive conflict in the history of the UNSC. By the end of the war, billions of humans had lost their lives along with a sizable portion of their armed forces. After the Schism (mentioned above), the Covenant Loyalists are defeated and the Covenant empire collapses after the death of the Prophet of Truth.

The threat posed by the Flood under the command of the Gravemind is also substantially reduced after the Ark (an ancient Forerunner station) is destroyed along with millions of flood spores on the surface.

Timeline of the Conflict

• Feb 03. 2525 - Communications with the peaceful outer colony of Harvest are lost after having reporting contact with a unknown ship. A small scout ship, the Argo, is sent to investigate.
• Apr 20. 2525 - The Argo arrives at Harvest and makes a brief report; the ship is never heard from again.
• Oct 07. 2525 - A UNSC battle group consisting of two frigates and a destroyer is sent to Harvest. There they discover that the surface is glassed (fused into glass by intense heat) and find one ship in a geostationary orbit over the colony. The ship attacks the battle group, destroying both frigates and badly damaging the destroyer.
• Nov 01. 2525 - Vice Admiral Preston Cole begins to mobilize the largest UNSC fleet in history to retake Harvest from the Covenant.
• In 2531 - Cole's fleet retakes Harvest at a tremendous cost; 2/3rds of his fleet is destroyed.
• In 2532 - Events of Halo Wars take place.
• In 2535 - The Cole Protocol, or 'United Nations Space Command Emergency Priority Order 098831A-1', is initiated. This order bars any ship from traveling directly to the inner colonies as it could inadvertently give away their position. As such, ships must generate randomized exit vectors.
• In 2536 - After wiping out almost all of the outer UNSC colonies, the Covenant start attacking their inner colonies; morale is beginning to run dangerously low as the UNSC rarely win any of the battles.
• 2536 - 2552 - Covenant keep pushing into the inner colonies and even with the help of the Spartans the tide of the battle cannot be reversed.
• Jul 17. 2552 - The human colony of Sigma Octanus comes under attack and Commander Jacob Keyes successfully defends the colony against overwhelming odds. He is promoted to Captain.
• Jul 23.2552 - The Fleet of Valiant Prudence is sent to the Epsilon Eridani system to begin the attack on Reach and to prepare the Fleet of Particular Justice for the main offensive.Fireteam 3 Charlie, along with other special warfare fireteams under command of Colonel Holland, are sent to invetigate Visegrad after contact with the comms relay is lost.
• Jul 24.2552 - Noble Team is ordered to investigate a possible Insurrectionist activity at the disabled Visegrád Relay. Shortly after, the team learns that the Covenant are responsible for the attack on the relay. After retaking the relay, Noble Team discovers a data module on one of the dead staff. WINTER CONTINGENCY is declared.
• Aug 25.2552 - The Pillar of Autumn is chosen for a special mission by Dr. Catherine Halsey and Jacob Keyes is chosen to captain her. Assisting him in the mission is Cortana and Master Chief.
• Aug 29.2552- SPARTAN-B312 and a team of ODSTs secure a landing zone for Noble Team's Falcon. Later Noble Team proceeds inside Sword Base only to learn their true mission: escort a part of Cortana to the Pillar of Autumn.
• Aug 30.2552 - Before the Autumn can begin its mission, Reach is attacked and every ship in a three system vicinity moves in to help defend Reach. A majority of the Spartans fight on the ground to help defend the planet and are believed to be lost when the Covenant glass the planet. The fleet over Reach is obliterated and the MC escapes aboard the Pillar of Autumn. He is believed to the last remaining Spartan. Spartan-B312 was killed by a group of elites.
• Sep 04.2552 - Lt. Wagner reports to the high command on Earth and formally informs them of the loss of Reach. He also mentions the very real possibility that the Spartans have been all but wiped out.
• Sep 07 2552 - On Reach, Dr. Halsey and a small number of Spartans are holed out underground, later joined by Admiral Whitcomb. They discover an ancient cavern that among other things contains a forerunner crystal. Dr. Halsey takes the Crystal for research.
• Sep 19.2552 - The Pillar of Autumn arrives at Alpha Halo and, after a brief skirmish, is crash landed by Jacob Keyes on the Halo's surface. A significant amount of the onboard marine force is killed trying to repel boarders but the survivors escape to the planet's surface under the command of ODST Major. Silva. Cortana and the Master Chief also escape to the surface of the planet where they help in setting up a temporary base of operations. Captain Keyes and several high ranking officers are captured by the Covenant and all but the Captain are executed.
• Sep 20/21.2552 - When the flood is discovered on Halo, the Covenant High Command orders every ship in the vicinity of Halo to jump to slipspace and "abandon" the ring. This is done out of fear of the parasite possibly spreading to other areas of the galaxy. This move costs them dearly as they are not able to resupply their troops efficiently and quickly.
• Sep 22.2552 - The Master Chief and Cortana escape aboard a fighter after rigging the reactor of the Pillar of Autumn to explode, thereby destroying both the Halo and the flood threat on board. Major Silva and his troops commandeer an infested Covenant ship and attempt to escape from the surface of the planet but are killed when the ship crashes.
• Sep 23.2552 - The Master Chief along with Sgt. Johnson, Lt. Haverson, Locklear and Polaski successfully board and take control of a covenant flagship (The Ascendant Justice) that had come to investigate the destruction of Halo, and they take it to Reach.
• UNKNOWN/ SPACE-TIME ANOMALY - Chief returns to Reach and mounts a rescue; when in slipspace, the forerunner crystal previously picked up by Dr. Halsey is shown to have curious space/time manipulation powers. As such the date is actually closer to Sep.12 2552. After a battle in an altered state of slip space, the Ascendant Justice is heavily damage and is taken to a pirate colony for repairs. A few Spartans are killed when they try to repair the ship while in slip-space and this brings the total number of surviving Spartans to a single digit. Dr. Halsey drugs Kelly and escapes with her on a shuttle and before she leaves; she gives the forerunner crystal to Locklear with orders to destroy it; which he does (although he is killed by the radiation from the subsequent blast).
• UNKNOWN/ SPACE-TIME ANOMALY- Cortana discovers the Covenant's plan to invade Earth and finds that the rally point for their fleet is at a command and control station called Unyielding Hierophant. Master Chief and the surviving Spartans infiltrate the facility and set the core to detonate. Admiral Whitcomb and Lt. Haverson, aboard the crippled Ascendant Justice, coax the covenant forces into following them close to the station which explodes killing them as well as the majority of the covenant fleet. John, Linda, Will, and Fred (the last known remaining Spartans), along with Sgt. Johnson and Cortana, depart for Earth to warn them of the Covenant's plans.
• Oct 20.2552 - MC, Johnson and Keyes are (posthumously) decorated, and the previous Supreme Commander of the fleet of Particular Justice, the one responsible for safeguarding Halo, is branded a heretic and punished, thus instead becoming the Arbiter. The first battle of Earth takes place; the Chief goes ground -side to New Mombasa to repel the Covenant there and then returns to the In Amber Clad. Shortly thereafter he follows the Prophet of Regret when he escapes to Delta Halo. Once there the events of Halo 2 take place.
• Nov 03.2552 - Dr.Halsey and Kelly arrive on Onyx and are attacked by the sentinels there, once on the ground they team up with Kurt and the Spartan-III's. She also puts in a request to have all the Spartans meet her at Onyx. Fred, Will, and Linda are dispatched to Onyx, hijacking a Covenant Cruiser on the way. The Covenant however becomes aware of the ship and its final destination. Plans are drawn up by the Separatists to go to Onyx to reclaim lost Forerunner technology.** The shield world is turned on and the remaining Spartans along with Halsey are pulled into the "void". The contingent of Elites that had landed on the planet to attack were all killed when Kurt sacrificed himself to activate a nuclear warhead.
• 2552 - 2553 - The events of Halo 3 take place. The second battle for Earth begins and the portal on Earth is activated leading to The Ark. Miranda Keyes is killed by Truth; Sgt. Johnson is killed by 343 Guilty Spark when he tries to activate the replacement ring. The Brute fleets are destroyed by the Elites and the Prophet of Truth is killed by the Arbiter, thereby disrupting the Covenant loyalists. The Ark is destroyed when the replacement ring activates, taking out the Gravemind and any Flood that were on the surface. The Arbiter escapes through the portal to Earth but the Chief's part of the ship is sheared off, to be later seen floating in space at the end of Halo 3.
• Mar 03.2553 - The Human-Covenant war ends and a memorial is built in remembrance of the victims; the Chief is thought to be dead but, following the protocol that Spartans never die, he is declared MIA - as are the rest of the Spartans.

It should be noted that although the Master Chief and the Arbiter worked together during the events of Halo 2, humans and the Covenant are still not allied at this point in the timeline.