Planet of Origin: Arnessk, in the Milky Way galaxy, which they inahbited 12 000 years ago until the planet became inhabitable due an alien attack..
The Eidelons is an advanced pacifist humanoid species which possesses a gland in their head that acts as an empathic receptor, allowing the Eidelon to sense the wants and desires of those nearby, and vibrates to create an energy field which helps them develop tranquility and rationality. Using these powers, the ancient Eidelons could devise compromises that met the goals of the involved conflicting parties and could ensure that a peaceful solution to conflicts would be accepted. Eidelons look remarkably like humans but have an internal very different cranial structure, being able to open up the upper part of their head when their gland is in action.
Looking for a species to serve both as bodyguards and as enforcers of peace. They abducted primitve humans on planet Earth some 27,000 years ago and genetically enhanced them. This new species became known as the Sebaceans and they became the Eidelons' trusted acolytes. They took on the name of Peacekeepers due to their function.
After Arnessk became uninhabitable and the Eidelons has vanished (either fleeing to other planets or entering suspended animation outside of time. The Peacekeepers attempted to carry and kept the peace with military force, and eventually became the militaristic Peacekeeper empire.Today, only a handful of Eidelons remain.
SOurce: Farscape Universe.