A timeline of all major events in the Halo universe from the time of the Forerunners through the rule of the Created.
The Jovian Moons Campaign was a brief conflict in 2160 between the corporate-backed Friedens and the neo-communist Koslovics on several of the Jovian moons, spurred by a Frieden attack on a team of colonial advisers sent by the United Nations to help police the often violent region.
The Rainforest Wars was a large-scale conflict from 2162 to 2163 between the fascist Friedens, the neo-communist Koslovics, and the forces of the United Nations on the continent of South America.
The Mars Campaign was a retaliatory strike in December 2163 by the United Nations to eliminate the Koslovics, a rebel organizations labeled as terrorists by the UN.
The Interplanetary War was a six-year conflict between the United Nations, neo-communists known as the Koslovics, and the corporate-backed Friedens, an movement with strong fascist roots.
The first permutation of the Orion Project, the predecessor to the future Spartan programs in the 26th century, was initiated on April 13th, 2321, consisting of five test candidates.
The Domus Diaspora was a time period during humanity’s expansion into the galaxy that saw massive colonization efforts of hundreds of colony worlds in the span of around thirty years, starting in 2362.
The colony world of Reach, the first ever extrasolar colony established by humanity, was colonized sometime in 2362 by the colony ship Odyssey.
The colony world of Arcadia, one of the many outer worlds to be colonized in the 25th century, was settled sometime in 2429.
The colony world of Meridian, a moon orbiting Hestia V in the Hestia system, was an outer colony world colonized sometime in 2431.
The outer colony world of Harvest, one of the youngest human colonies, was settled sometime in 2468.
In 2491, the Office of Naval Intelligence re-instituted the Orion Project, an attempt to create engineered super-soldiers to boost combat effectiveness.
The Far Isle Rebellion was a major uprising on the outer colony world of Far Isle in 2492 that is largely cited in spurring the Insurrection.
The Callisto Incident was a series of events involving the UNSC Callisto that is considered the first true insurrectionist attack from January to March 2494.
Operation: TREBUCHET was a twelve-year UNSC operation to quell growing unrest and insurrectionist activities in the outer colonies from 2513 until the start of the Human-Covenant War in 2525.
The Raid on UNSC Infinity was an attempted infiltration and commandeering of the UNSC Infinity by insurrectionist forces calling themselves the New Colonial Alliance in January 2553.
The Voi Memorial was erected in March 2553, marking the end of the Human-Covenant War and to remember all who were lost during the conflict.
Operation: JOVIAN WHISTLE was an operation executed by the UNSC 717th Xeno-Materials Exploitation Battalion to recover a Forerunner ancilla on the human colony world of Gao in the Cordoba system in the early summer 2553.
The Battle of Draetheus V was an attack by former Covenant forces under the command of Sangheili Zealot Merg Vol on the colony world of Draetheus V and its moon X50 sometime in 2554.
Operation: FAR STORM was a joint UNSC and Swords of Sanghelios mission to reactivate the Portal at Voi and travel back to Installation 00 after discovering the Halo array was counting down to activation in March 2555.
The Invasion of Earth was an attempt by the monitor of Installation 00 to harvest the Earth for resources to repair the Ark when the Portal at Voi was reopened in March of 2555.
The Mission to Cleyell was a UNSC mission to the colony world of Cleyell, which had recently been glassed by a fringe group of Covenant remnants sometime in 2556.
The Battle of Requiem was a conflict between former Covenant forces under the command of Jul 'Mdama, UNSC forces from the UNSC Infinity and Forward unto Dawn, and Promethean forces under command of the Ur-Didact on Forerunner Shield World 0001, also known as Requiem, in July 2557.
The Battle of Installation 03 was a battle between the UNSC and Covenant remnant forces under command of Jul 'Mdama on Gamma Halo during and immediately following the New Phoenix Incident in July 2557.
The Mission to Installation 03 was a UNSC operation to investigate the loss of contact with a science outpost and Spartan-II Black Team on Gamma Halo immediately following the New Phoenix Incident in July 2557.
The Battle of New Phoenix was a military engagement between the UNSC and Covenant remnant forces under command of Jul 'Mdama in the city of New Phoenix on Earth, immediately after the New Phoenix Incident and the Battle of Installation 03 in July 2557.
The Requiem Campaign was a UNSC mission to return to Requiem, and take control of the shield world away from Jul 'Mdama and his Covenant remnants in February 2558, six months after the Battle of Requiem.
The Battle of Ealen IV was an attack on peace negotiations between the Sangheili and Jiralhanae on Ealen IV in the Ealen system in March 2558.
The Ambush at Oth Lodon was an attempt by the New Colonial Alliance to destroy the UNSC Infinity and kill Admiral Hood after the failed assassination attempt at Ealen IV days earlier.
Operation: WHISTLE STOP was a UNSC and ONI mission to recover a potential bio-weapon from a group of Sangheili and Kig-Yar pirates on the planet Ven-III in May 2558.
The Battle of Oban was a conflict between the UNSC and Covenant forces under command of Jul 'Mdama on the colony world of Oban in July 2558.
The Battle of Aktis IV was a conflict between the UNSC forces aboard the Infinity and the Covenant forces under command of Jul 'Mdama on the planet of Aktis IV in July 2558.
Operation: ATHENA was a covert UNSC mission to infiltrate the Song of Retribution, and retrieve the Janus Key from Jul 'Mdama and his Covenant remnant forces in September 2558.
The Battle of Kamchatka was a battle between Covenant remnant forces under the leadership of Jul 'Mdama, local Promethean forces under control of Cortana, and the UNSC in the form of Spartan-IV Fireteam Osiris on the planet of Kamchatka in October 2558.
Operation: BIRD IN HAND was a UNSC mission carried out by Spartan-II Blue Team to infiltrate and recover the Office of Naval Intelligence research vessel Argent Moon on October 23rd, 2558.
The Battle of Genesis was an engagement between the UNSC, Promethean forces under command of Cortana, and the remains of Jul 'Mdama's Covenant forces on the artificial Forerunner installation known as Genesis in October 2558.
The Second Battle of Meridian was a conflict between the colonists of Meridian funded by the Liang-Dortmund Corporation, the UNSC, and Prometheans under control of Cortana on October 25th, 2558.
The Second Ark Conflict was a battle between the UNSC forces aboard the Spirit of Fire and the Banished forces under command of Atriox on Installation 00 in 2559.
Operation: WOLFE was a UNSC mission on the planet Reach in October 2559 to recover several cryobins from CASTLE Base under Menachite Mountain for Doctor Catherine Halsey.
The Installation 07 Conflict was a battle between UNSC forces led by John-117 and the Banished on Zeta Halo between December 12th, 2559 and May 31st, 2560.
