For millenniums Centre tried to impose its code on the whole of Known Space. It proved impossible.

So now it has drawn back its limits to a federation of six planets, each within ten standard days' travel. It concentrates on preserving Centre as the epitome of civilisation.

The consequence of this decision is that those living within Centre have value. Those beyond Centre's limits do not.

The current interstellar human civilisation, based around Centre, is about 25,000 standard years old.

It was founded by a group of young idealists. They opposed the established view that any interstellar civilisation was intrinsically corrupt. They believed that a code of behaviour could ensure that the benefits of interstellar trade would benefit everyone.

They used an ancient spacecraft with a Mulligan drive to make contact with another colonised system. Slowly, ship by ship, planet by planet, generation by generation, Centre was established.

Then, ten generations on, their descendents made contact with a secretive group who claimed to know how to build Mulligan drives. If it were true, the number of ships with Mulligan drives could be increased tenfold. If it were true, they could consider gating holes, opening interstellar travel to the masses.

Millenniums on, the Gaters are still providing the Mulligan drives and gates that link Known Space. Millenniums on, no one claiming to have met a Gater has ever been able to prove it.
There have been at least two interstellar human civilisations before the one initiated by Centre.

Centralite historians call the previous interstellar civilisation The Oligarchy. Immense power was in the hands of a small number of people, estimates vary between fifty and two hundred, called The Elite. The Elite extended their lives using all the technology available, including going into stasis for centuries until one scheme or another came to fruition. They kept the technology required for interstellar travel, the Mulligan drive, to themselves, trapping their subject populations within their home systems.

The Elite literally played god. Some created societies to worship them. Others would colonise a planet with a genetically engineered population just to provide a steady supply of a variety of human that they valued. A few sated their curiosity with ever more extreme experiments.

Finally, after millenniums, they were toppled by those they exploited.
Long before the Oligarchy there was the civilisation that some scholars call the Following Wave.

Two facts are known. The first is that the Following Wave were the first humans to travel through space via holes. Previously interstellar travel took centuries. Drone ships transported crews and colonists in stasis or generation after generation lived and died on the ships that would deliver their descendents to their destination.

The second is that the people of the Following Wave included Tronnies.

Legends say that each Tronny started out as an ordinary human. The patterns from his or her brain were imprinted on a crystal array and his or her thoughts were replicated using electronic circuits. Freed of the constraints of an organic brain each Tronny expanded its intelligence and consciousness.

Tronnies achieved the impossible. It is said that one invented the Mulligan drive.

Then one Tronny went on a rampage; an orgy of destruction.

Then another.

And another.

Tronies were judged too dangerous to exist. By the time they were eliminated only the ruin of the Following Wave remained.