A timeline of all major events in the Halo universe from the time of the Forerunners through the rule of the Created.
Operation: GREY VEIL was an Office of Naval Intelligence mission to assassinate a Covenant Prophet on the planet Heian sometime in 2541.
The Battle for Alluvion was a major conflict in the Human-Covenant War that took place in the Bhaakto system some time in 2542.
The Battle of Psi Serpentis was a major conflict between a UNSC fleet of 162 warships led by the UNSC Everest and Admiral Preston Cole and two fleets of Covenant warships totaling over 300 ships in the Psi Serpentis system in April 2543.
The Battle of Miridem was an engagement between human and Covenant forces on and around the colony of Miridem.
The flagship of the UNSC Navy and the first Infinity-class supercarrier ever constructed, the UNSC Infinity is the largest single human warship ever constructed, with a crew of over 17,000.
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.
Spartan-III Gamma Company was the last of three Spartan-III companies to be recruited, trained, and put into service.
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.
The Battle of New Llanelli was an engagement between UNSC and Covenant forces on the colony world of New Llanelli in the Brunel system, sometime in 2546.
The Battle of Sargasso was a conflict between invading Covenant and defending UNSC forces on the colony of Sargasso on September 21st, 2546.
The Battle of Skopje was a conflict between the Covenant and UNSC forces on the colony world of Skopje, sometime in 2547.
In an effort to boost morale, the Office of Naval Intelligence made public the existence of the Spartan-II program and the accomplishments of the Spartan-IIs in May, 2547.
The Battle of Meridian was a three-year conflict between the Covenant and UNSC forces on and around the colony world of Meridian, a moon around Hestia V in the Hestia system, between 2548 and 2551.
The Siege of Paris IV was a major battle between the UNSC and Covenant forces on and around the colony of Paris IV in the Paris system in 2549.
The Algolis Invasion was a Covenant attack on the human colony world of Algolis in the Algol system sometime between 2548 and 2552.
The Fall of Arcadia, also known as the Second Fall of Arcadia, was a Covenant invasion and subsequent loss of the colony world of Arcadia in the Procyon system on September 9th 2549.
