The Covenant are a fictional theocratic hegemony of alien races who serve as the main antagonists in the first trilogy of the "Halo" video game series. They are composed of a diverse array of species united under the religious worship of the extinct Forerunners and their belief that the Forerunner ring worlds known as Halos will provide a path to salvation, known as the ""Great Journey"". After the high Covenant leadership—the three High Prophets—discover that the existence of the human species directly contradicts their ancient religion, they declare a genocidal campaign against humanity to preserve their own political power, knowing if they revealed this information to the rest of the Covenant it would mean the hegemony would fall into chaos. The High Prophets claimed the extermination of humanity is the "will of the gods and we Covenant are their gods' instrument." Over the next 27 years of war, the Covenant would repeatedly overpower the technologically inferior human race and its United Nations Space Command, devastating hundreds of human colonies throughout the Orion Arm, killing billions in their campaign. The Covenant are ultimately defeated during the final battle of the war set on the Ark, a Forerunner world, in "Halo 3". With the Covenant destroyed, its former members create new factions with differing ideologies.