A timeline of all major events in the Halo universe from the time of the Forerunners through the rule of the Created.
The Battle of Installation 04 was an engagement between the UNSC Pillar of Autumn and the Covenant Fleet of Particular Justice on and around the Forerunner megastructure known as Installation 04, or Alpha Halo, in the Soell system.
The Battle of Installation 05 was an engagement between the Covenant forces, including those that fled the Battle for Earth, High Charity, and the Second Fleet of Homogeneous Clarity, and the UNSC-allied forces, including the UNSC In Amber Clad led by Miranda Keyes, and the Fleet of Retribution led by the Arbiter Thel 'Vadam.
The Battle of Installation 00 was a major conflict between the forces stationed aboard the UNSC Forward Unto Dawn and Arbiter Thel 'Vadam's Fleet of Retribution, and the Covenant fleet loyal to the Prophet of Truth.
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.
The Mission to Mount Kilimanjaro was a trek undertaken by 343 Guilty Spark, Rion Forge, and the crew of the Ace of Spades to find the Librarian and, in the case of Spark, gain access to the Domain in September 2557.
The discovery of Bastion was the culmination of a series of events involving 343 Guilty Spark and Rion Forge that led to the discovery of the Librarian’s shield world.
