War of Beginnings (Earth-5875)

"So full of hate were our eyes that none of us could see. Our war would yield countless dead, but never victory."

- - Writ of Union

The War of Beginnings was a major war in the Urs system fought between the sangheili and the san'shyuum Reformists over ideological, religious, and technological differences and views over the forerunners. Waging for one hundred years, it finally ended on Sanghelios with the ratification of the Writ of Union and the kindling of the Covenant.

War
In 938 BCE, the san'shyuum Reformists found the planet Ulgethon, where they encountered the sangheili, discovering the planet to be one of the species' colonies. Upon landing on the planet, they took notice of the abundance of forerunner artifacts that were left behind by the forerunners to study it. However, the sangheili also worshiped the forerunners as gods, and, unlike the Reformists, had divergent ideological views on the handling of the relics, which soon developed into the War of Beginnings in 938 BCE, when an Arbiter decapitated all members of a san'shyuum embassy, delivering their heads back to the Reformists.

The sangheili believed every forerunner relic to be sacred beyond measuring, and thus that they should not be touched or manipulated by lesser beings. The sangheili attacked the san'shyuum as soon as they could, and the War of Beginnings raged on for centuries. During the conflict, the sangheili had both a numeric and physical advantage. The military tactics of the sangheili surpassed that of the san'shyuum, and one sangheili warrior was worth ten san'shyuum soldiers, as they were much stronger and faster. However, the san'shyuum had more advanced technology, huragok that could repair and maintain their military technology, and control over the Dreadnought, which was able to tear down hundreds of sangheili warriors and ships.

As the war continued with no apparent end, both species came to fear ultimate annihilation on the two sides. The sangheili feared the Dreadnought and their possible extinction at its power, while the san'shyuum feared for their existence with their dwindling numbers and inability to sustain their females and children. The war became so devastating that the sangheili collectively agreed to abandon their own religious beliefs and study and incorporate forerunner technology to their arsenal to avoid total destruction. Such an act allowed the sangheili to go stalemate against the san'shyuum, but the Dreadnought still proved to be unstoppable, and so the sangheili unwillingly surrendered.

Aftermath
"So let us cast arms aside, and like discard our wrath. Thou, in faith, will keep us safe, whilst we find the Path."

- - Writ of Union

Even in the past, sangheili held numerous beliefs related to honor and battles, and so they respected a worthy adversary. After the end of the war and the sangheili's surrender, the san'shyuum proposed an alliance between the two species. In 852 BCE, a truce between the two species, between the sangheili and san'shyuum leaders Pelahsar the Strident and High Lord Mken 'Scre'ah'ben, where both sides agreed to move on their past crimes against each and cooperate towards an alliance: the result was the ratification of the Writ of Union and the formation of the Covenant. For the next decades, the sangheili homeplanet Sanghelios served as the capital remained the center of the Covenant, as the two forces used their own engineering tactics and the huragok to build a mobile capital city for the alliance, High Charity.