The Covenant Empire also knownas the Covenant, is a pact between many different alien species that controls a large ortion of the Orion Arm of the Milky Wat Galaxy. The Covenant is a political, military and religous affliation formed at the end of the San'Shyuum-Sangheili war which was originally an alliance between the two races. It expansion included the incorporation of six other species that wordhip the Forerunners and the Halo Array after its original formation. The Covenant then waged a genocidal war against Humanity that lasted for a period of 28 years until they were defeated due to a number of factors - this included an internal struggle between Elites and the rest of the Covenant and the loss of the Covenant's leadership during the infestation of High Charity by the Flood and during the Battle of Instillation 00. Even thoguh the Covenant loss the war, a splinter faction of Sangheili Loyalists known as the Covenant Remnants: this terrorist group is deemed hostile to Humanity after they broke the truce between Humanity and the Covenant at the end of the war. They seem to be able to weild a large number of warships but their exact streength is unknown by Humanity as is information about any other splinter faction of the Covenant.
in the year 938 BC, San'Shyuum reformists entered Sangheili-occupied space which led to first contact between the San'Syuum and the Sangeili. The San'Shyuum, who came to Sanghelios to recover and study ancient Forerunner artifacts on the planet. They soon found out that they had diffrences on how the artifacts should be handled