The sangheili are an honorbale race that fought proudly for the Old Covenant. They were the Old Covenant's most cherished race until the mad prophets betrayed them.
The Old Covenant[]
The sangheili were treated as surperior to all of the other old covenant races. Unfortunately, the prophets knew the sangheili were getting to powerful and they feared the sangheili and their influence could overthrow the Old Covenant. To avoid this problem the prophets used the Jaralhanse and told them that they were the new great race since the sangheili were no longer fit to lead the Old Covenant armies.
The Jaralhanse and other Old Covenant warriors started wiping out many Sangheili and soon many Sangheili made an alliance with humans to help defeat the Old Covenant. After the Old Covenant finally collapsed, a few covenant abandoned their old ideals and decided to live iscolated from most species. Then the reamant was formed by sangheili which deicated itself to make a new better Covenant that treated all species fairly and would restore honor to the sangheili.