The Banished are a Covenant splinter faction serving as the antagonists of Halo Wars 2.
They are led by named Atriox and most of their leadership appears to be comprised of Jiralhanae. They also have several Sangheili mercenary groups working for them, and an army comprised of Unggoy and a few Mgalekgolo. They are extremely dangerous since not even the Covenent at the peak of their power is able to exterminate The Banished while they nearly destroyed humanity in the past.
In the year 2559, the Banished set foot on the Forerunner Ark and attempted to take control of it, causing them to come into conflict with the crew of the UNSC Spirit of Fire.