A timeline of all major events in the Halo universe from the time of the Forerunners through the rule of the Created.
The Blooding Years is the Sangheili term for the civil war that raged for five years on Sanghelios and throughout Sangheili-occupied territories following the end of the Human-Covenant War and disappearance of the San’Shyuum.
The Siege at Kolaar was an attack on Arbiter Thel 'Vadam and his forces by Avu Med 'Telcam and the Servants of the Abiding Truth in the first major conflict of the Sangheili civil war.
The Skirmish on Pious Inquisitor was a small battle that took place between ONI intel unit Kilo-Five and Kig-Yar pirates on the CCS-class battlecruiser Pious Inquisitor in the Shaps system in April 2553.
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 Attack on Rahnelo was an unprovoked attack by the San'Shyuum Prelate Tem'Bhetek, directed by the former Covenant Minister of Preparation Boru'a'Neem, on the Sangheili colony world of Rahnelo towards the end of 2553.
The Ambush at Duraan was the second part of the prelate Tem'Bhetek's plan to lure in the Shadow of Intent, capture the ship, and kill Rtas 'Vadum.
The Battle of the Prototype Halo Installation was a conflict between Tem'Bhetek, the former Covenant Minister of Preparation Boru'a'Neem, and the Shadow of Intent crew including Rtas 'Vadum and Tul 'Juran.
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 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.
The Sedra City Mall Bombing was a terrorist attack on the human colony world of Sedra in the Orrichon system by an unknown Sangheili terrorist organization in February 2556.
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.
Following discovery of the last known location of the UNSC Spirit of Fire from the Battle of the Etran Harborage, the Office of Naval Intelligence sent the UNSC Taurokado to investigate the system for any information regarding the whereabouts of the lost UNSC warship.
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 Raid on Ivanoff Station was an attack by the Ur-Didact and his ship Mantle's Approach on the Office of Naval Intelligence research facility Ivanoff Station nearby Halo Installation 03 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.
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 Nuusra was a battle between the remnants of Jul 'Mdama's Covenant forces, the Swords of Sanghelios, and Spartan-IV Fireteam Osiris in the sate of Nuusra on the continent Qivro on the Sangheili homeworld of Sanghelios on October 27th, 2558.
The Battle of Sunaion was a battle between the Swords of Sanghelios led by Thel 'Vadam, their allies Fireteam Osiris led by Jameson Locke, the last of Jul 'Mdama's Covenant forces, and the Created forces led by the Warden Eternal in the state of Sunaion on the Sangheili homeworld of Sanghelios.
