The Sangheili (Latin Macto Cognatus  meaning "I glorify my kin") are a saurian species of strong, proud, and intelligent warriors, as well as skilled combat tacticians. The Sangheili are named after their home planet, Sanghelios. They are known to humans as Elites. Due to their skill in combat, the Sangheili have formed the military backbone of the Covenant for almost the entirety of its existence. They had a very strong rivalry with the Jiralhanae, which finally boiled over into open hatred during the Great Schism, and the conclusion of the Human-Covenant war.
Originally a founding member of the unified conglomerate of races known as the Covenant, they later led the breakaway faction known as the Swords of Sanghelios, who sided with the humans against their former allies due to the fact that the Prophets of Truth and Mercy had ordered the genocide of the entire Sangheili race. This was established after the assassination of the Prophet of Regret at the hands of John-117, as it was the Sangheili who were ultimately held responsible for Regret's death, and they were seen as "unfit" to continue to guard the San 'Shyuum. The Prophets sought to achieve this through use of the other Covenant races, primarily the Jiralhanae.