A timeline of all major events in the Halo universe from the time of the Forerunners through the rule of the Created.
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.
Operation: SILENT STORM was a UNSC operation to use EVA tactics to infiltrate Covenant vessels and either capture or destroy them from within early in the Human-Covenant War in March and April 2526.
Operation: PROMETHEUS was an assault on a Covenant shipyard located on and around asteroid K7-49 by Spartan-III Alpha Company.
Operation: GREY VEIL was an Office of Naval Intelligence mission to assassinate a Covenant Prophet on the planet Heian sometime in 2541.
Operation: WARM BLANKET was an operation to recover Doctor Halsey from the Covenant after her capture during the Battle of Miridem in 2544.
Operation: IRON FIST was a military operation on the colony of Miridem after the Battle of Miridem in 2544 and prior to the colony's glassing.
Operation: TORPEDO was a mission by Spartan-III Beta Company to infiltrate and destroy a Covenant refinery on Pegasi Delta, the moon of 51 Pegasi B in the 51 Pegasi system.
Operation: FIRESIDE was an ODST mission to investigate a distress call sent by civilians on the colony world of Ariel, which had come under attack by Covenant forces days earlier in late December 2551 or early January 2552.
Operation: RED FLAG was a planned operation by both the Office of Naval Intelligence and the UNSC to use Spartans to capture a Covenant ship, use it to penetrate into Covenant space, and capture a Hierarch, with the intent of using the Prophet to broker a cease-fire.
Operation: SUNSPEAR was a mission to infiltrate Covenant space and destroy a major population center as an act of revenge for the Fall of Reach at the end of 2552.
Operation: RETRIBUTION was an Office of Naval Intelligence mission headed by operative Veta Lopis and her Ferret team to investigate the murder of Vice Admiral Graselyn Tuwa and the kidnapping of her family members on December 6th, 2553.
The Return to Installation 00 was an Office of Naval Intelligence mission undertaken by the UNSC Rubicon to return to the Ark following the Battle of Installation 00 and investigate the status of the facility in August 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 Mission to Alpha Shard was a joint ONI and Sedran Colonial Guard mission to secure and eliminate the source of the bio-weapon used in the Sedra City Mall Bombing in February 2556.
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 Assassination of Avu Med 'Telcam was an assassination sanctioned by the Office of Naval Intelligence Section Three and carried out by SPARTAN-G059 on the leader of the Servants of the Abiding Truth on former colony world New Llanelli in the Brunel system in January 2558.
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.
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.
ONI agent Lieutenant Parisa, is sent on a mission to deliver an encryption key to John-117 behind enemy lines prior to the Battle of Installation 07.
