From Halopedia, the Halo wiki
Joori's Light was a Blockade Runner of the Sangheili, named in reference to the star Joori. Joori's Light was a legendary ship of the War of Beginnings, in which the ship succeeded in evading destruction and capture at the hands of the San'Shyuum during the war. When the war came to an end and the Covenant was established through the Writ of Union, the crew of Joori's Light refused to join the Covenant and instead escaped to uncharted space, and were never heard from again. During the time of the Covenant, Sangheili told each other hushed war-stories of the legacy of Joori's Light.