Second Base

Second Base, along with Green Hills, was one of two colonies lost directly after Harvest in the Human-Covenant War. Initially, the UNSC had hoped to cover up their loss by explaining it away as a communications blackout caused by Insurrectionists. Eventually, they revealed that the UNSC was now fighting a xenocidal alien hegemony, and that this and another colony had been destroyed with the total loss of two million civilians between them.

List of appearances

 * Halo Wars: Genesis
 * Halo: Reach
 * Data pads