~125,000 BCE

Around 125,000 BCE, the Forerunners built the crown jewel of their civilization, an artificial world that served as the center of all Forerunner governance, Maethrillian.

~500 Mya

Sometime long before the time of the Forerunners, the Precursors created the Domain, a repository of all knowledge in the universe. The exact date is unknown, and while some sources say it was created 500 million years ago, others say it has existed for billions of years.

~15 Mya

Around fifteen million years ago, the Forerunner race was created by the Precursors in an effort to make a new species that could assume the Mantle of Responsibility.

~10 Mya

Ten million years ago, the Precursors, the species that populated the galaxy with intelligent life including Forerunners, determined the Forerunners were a failed experiment and decided to remove them from the Milky Way galaxy.

2200 BCE - 2100 BCE

The War of Wills was a fierce and prolonged conflict between two factions of the San’Shyuum: The Stoics who wanted to worship Forerunner technology but never use it, and the Reformists who wanted to take advantage of the incredible Forerunner artifacts around the galaxy.

938 BCE - 852 BCE

The War of Beginnings was an eighty-six year conflict between the San’Shyuum Reformists who escaped Janjur Qom after the War of Wills and the Sangheili species between 938 and 852 BCE.

860 BCE

The Skirmish of the Planet of Blue and Red was a conflict between the San’Shyuum and Sangheili during the War of Beginnings in 860 BCE.

852 BCE

The Writ of Union was a declaration of peace between the San’Shyuum and the Sangheili, as well as the formation of the Covenant, signed by both species in 852 BCE.

852 BCE - 791 BCE

The Writ of Union not only formed an alliance between the Sangheili and the San’Shyuum, but also commissioned the construction of a great holy city of the Covenant, known as High Charity.

850 BCE

Following the end of the War of Beginnings, the San’Shyuum undertook an effort to recover additional females for breeding purposes from their homeworld, known as the Mission to Janjur Qom.

850 BCE

The Rending was a planned disassembly of Shield World 0673, also known as the Refuge, by a group rebelling against the formation of the Covenant in 850 BCE.

789 BCE - 784 BCE

The Taming of the Lekgolo was a five-year campaign by the Covenant to first destroy, and later incorporate the Lekgolo into the Covenant hierarchy from 789 to 784 BCE.