The Second Martian Revolution, or the Revolution of 2125, was an extended period of hostilities primarily between the members of the Earth Defence Force stationed in the Tharsis region on Mars and the fledgling Red Faction insurgency recently resurrected with rumoured backing and involvement from the Commonwealth. The Marauders, a bitter warrior culture descended from displaced Ultor scientists and living amongst the furthest fringes of the Badlands, also engaged heavily in the fighting against both sides - although they did eventually ally with the colonist insurgency in the face of the EDF's trump card, the arrival in Mars-orbit of the E.D.S Hydra.