Humanity is nominally united in an interplanetary Empire, led from Earth by the Immortal Emperor Solomon Petresun. Petresun's policy is the defence of Earth at all costs. While Earth is prosperous and well protected, the colonies on Luna, Mars, and Venus suffer from increasingly harsh regulations and production quotas. The combat units of the Empire are represented by the Imperial Police, Terran Defense Force and the Imperial Knights. The former paramilitary group is responsible for maintaining order in the colonies. The Terran Defense Force are the standard military with bases from Mercury to Titan. The Knights, led by Grand Master Caanon Weathers, are the military's elite and are provided with the best pilots and equipment.