A timeline of all major events in the Halo universe from the time of the Forerunners through the rule of the Created.
In 2491, the Office of Naval Intelligence re-instituted the Orion Project, an attempt to create engineered super-soldiers to boost combat effectiveness.
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 First Battle of Harvest was humanity's first contact with the Covenant on the planet Harvest in the Epsilon Indi system and the subsequent destruction of the entire colony.
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.
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 Fall of Reach was possibly the largest battle during the Human-Covenant War, taking place in the Epsilon Eridani system, in orbit and on the ground of Reach, humanity's largest military stronghold.
The Massacre at Eridanus Secundus was a Covenant attack on a rebel facility within a series of asteroids in the Eridanus system in late 2552.
Operation: FIRST STRIKE was a mission undertaken by John-117 and several other Spartan-IIs to infiltrate and destroy the Covenant space station Unyielding Hierophant and associated armada of over 500 warships in the Tau Ceti system prior to the Covenant's invasion of Earth.
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 for Earth was a large-scale space, air, and ground battle between the invading Covenant forces and the UNSC Home Fleet on and around Earth at the end of 2552.
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.
