SUMMARY
At the start of the Covenant in 851 BCE, a group of Sangheili who did not agree with the peace being formed with the San'Shyuum, formed around their leader Ussa 'Xellus and escaped to a previously unknown Forerunner construct known as Shield World 0673. Though broken apart soon after the colony's formation, the Ussans lived on what they called The Refuge for over 3,000 years. After the Great Schism in 2553, the Prophet of Clarity Zo Resken, along with his ship Journey's Sustenance, discovered the Ussan colony and reintegrated it with the remaining Sangheili society.
RELATED MEDIA
These events are depicted in the novel Halo: Broken Circle.