Ages of Reclamation

The Ages of Reclamation were a series of events in the Covenant history during which the true search for the Halos began. It was the final age of Covenant history, as the Covenant split apart in the Great Schism at the conclusion of the age. The Ninth Age of Reclamation was the time in which the Human-Covenant War occurred, and began when the Minister of Fortitude became the Prophet of Truth and declared war on Humanity. The Age of Reclamation is represented by Forerunner metal.

Nine Ages of Reclamation have occurred as of 2552, according to the UNSC Military Calendar, but only the events of the Ninth are known in any great detail. The Ninth Age of Reclamation was probably the most desperate period for the Covenant in its history. At the end of the age, all three of their main religious leaders had been killed, and an entire species, the Sangheili, had successfully broken away from the majority of the hegemony, taking with them an unprecedented amount of personnel, equipment, and territory.

Beginning
The 9th Age of Reclamation began in the year 2525, the year that the Covenant came into contact with humanity for the first time, at the UNSC colony world of Harvest. According to the Luminary of the Minor Transgression, the world was filled with Forerunner glyphs, which the Covenant misinterpreted as "Reclamation". The true meaning, however, was "Reclaimer", and every human was covered with such a glyph, denoting them as the Reclaimers of the Forerunners. The Minister of Fortitude understood this revelation would shatter the Covenant's confidence in the teachings of the Prophets and the Great Journey, and thus declared humanity as a species to be heretics who threatened holy Forerunner relics and worlds. He was also sure that the war would lead them to other Relics that the Covenant could reclaim, and finally the Sacred Rings, beginning the Great Journey. This reasoning led the Covenant to begin the twenty-seven year long war with Humanity.

Human-Covenant War
As one of the first acts of the war, the planet Harvest was immediately glassed. Spartan-II super soldiers were deployed in the Battle of Chi Ceti, boarding a Covenant Frigate, planting explosives on the ship, and destroying it. The victory, however, came at a high cost. Samuel-034 was killed when the nuclear devices confiscated from the Pelican dropship were detonated because he had a breach in his suit which meant he would die if he went outside the ship.

Multiple engagements would ensue in the Outer Colonies, including the Second Battle of Harvest, which ended in the UNSC destroying a single Covenant vessel above Harvest. After this, the Covenant engaged the UNSC in a multitude of space battles, most of which the Covenant won due to their superior technology. Soon after the UNSC's retake of Harvest, the Covenant would return to the planet, resulting in a prolonged engagement for control of the planet. In 2530, the Covenant Empire attacked and glassed Eridanus II, home world of the Master Chief.

In 2535, the Covenant destroyed Jericho VII in the Battle of Jericho VII, and by that year, the Covenant were winning decisive victories against the UNSC, crushing and decimating its Outer Colonies. By 2536, Covenant militants swarmed into the UNSC Inner Colonies. For several years, human lives were spent in huge numbers winning ground operations, only to be wasted after the Covenant won the battle in space, glassing the Inner Colonies one after another.

Then, in 2537, Spartan-IIIs were trained and deployed in the battles of New Harmony, New Constantinople, and the Siege of the Atlas Moons. In Operation: PROMETHEUS, Spartan-III Alpha Company was slaughtered by Covenant forces. Noted however, they managed to succeed in their goal of destroying the reactors on the moon. In 2544, the minor Battle of Miridem took place. In 2545, Operation: TORPEDO resulted in the massacre of Spartan-III Beta Company at Pegasi Delta.

Installation 04
In 2552, the Battle of Sigma Octanus IV led to a major UNSC victory, but at the cost of the Covenant learning the location of Reach and Installation 04. During the Battle of Reach, the largest naval battle between the UNSC and the Covenant, Covenant forces won a decisive victory, destroying 152 UNSC ships and 20 Super MAC gun platforms. This was a major blow to the UNSC, who lost their last great stronghold, with the exception of Earth. A single UNSC ship, the UNSC Pillar of Autumn escaped to Installation 04. After four days of hard fighting in the Battle of Installation 04, the Covenant discovered the Flood organism and Forerunner constructs, which severely hampered their efforts to control the Installation. The melee ended with the destruction of Installation 04, an event that left only a handful of survivors.

Operation: FIRST STRIKE and the Arbiter
After discovering the location of planet Earth, the Prophet of Truth secretly commissioned a massive fleet to the station Unyielding Hierophant. However, before the fleet could invade Earth, in Operation: FIRST STRIKE, six SPARTAN-II Supersoldiers were able to rout and destroy all but a dozen of a fleet of 500 Covenant Starships at the sacrifice of Admiral Whitcomb and Lieutenant Haverson onboard Ascendant Justice. The survivors onboard the surveyed the damage and jumped to Earth, scoring a major UNSC victory. This slowed down Truth's efforts to assault Earth, forcing him to rebuild the fleet.

Not long after, the Prophet of Regret discovered the location of the Portal to the Ark. Unaware of the fact the planet was humanity's homeworld, he took a small task force of 15 ships to Earth. Meanwhile, the Commander of the Fleet of Particular Justice Thel 'Vadamee, the future Arbiter, who was tasked with defending Installation 04 was put on trial and marked as a Heretic to quell discontent within the High Council. Later, he became the Arbiter, embarking on a mission to quell a Heretic insurgency by Sesa 'Refumee, and a mission to retrieve the Index and the Oracle.

The Battle of Earth then occurred, as Regret engaged the UNSC above Earth despite being greatly outnumbered. Though the initial battle was relatively small and lopsided, (15 Covenant ships fighting 75 UNSC vessels and 300 MAC platforms), this event is significant in that the Covenant finally discovered the location of Earth. The UNSC emerged victorious over Regret's forces on the ground, and converged on Regret's ship, which was holding position where the gateway to the Ark was supposedly located, with the intent of capturing the Hierarch. However, Regret managed to discover the location of the next Halo ring, Installation 05 during the battle, and retreated to the new Halo. However, the battle was not over as Covenant reinforcements sent by Truth arrived just after Regret jumped, and assumed control over the battle.

Installation 05 and the end of the Ninth Age of Reclamation
The Covenant ship was pursued by five UNSC ships: the, , , , and. This resulted in the Battle of Installation 05. Again, a massive fight ensued between the UNSC, Covenant, Flood and Forerunner Constructs (Sentinels, Enforcers, etc). The Flood appear to have been in control of part of Installation 05. The onslaught of the Great Schism ended the 9th Age of Reclamation.

Progression of the Ages
During the Progression of the Ages, an appropriate dialogue is as followed:

Leader, or Chieftain: Reclamation.

Congregation, or Pack: ''Seventh! Journey and salvation!''

Trivia

 * The Covenant used the term "Reclamation" in describing their search for the Halos, possibly as they saw themselves as worthy of "reclaiming" Forerunner artifacts.
 * The Ninth Age of Reclamation was the only known Age where all of the Covenant Hierarchs died.
 * In Halo Wars, when playing as the Covenant, players can research the Age of Reclamation, improving all Covenant technology by one technology level. This allows the player to research the Covenant Uber Unit, the Scarab, symbolizing that this was the most important age to the Covenant.
 * The Age of Reclamation is one of the seven ages of the Covenant seen in a Halo 2 deleted scene, where the Prophet of Truth shows the Arbiter the Covenant's history.