It was used by the Guild of Adjudicators as a model of peaceful and just society. Until she learned of the existence of Serenity, Nyssa believed herself to be the last of her race, as Traken was destroyed by a wave of entropy in 1981. They were spared from the catastrophe by the Source, which was created there, before it was destroyed as well. (PROSE: Cold Fusion, TV: Logopolis)
After Mallador's entombment, Prophecy was set up as the new ruler in his place, and ruled for millennia. During Prophecy's rule, (AUDIO: The Guardians of Prophecy) an entropy wave destroyed the entire Traken Union,(TV: The Keeper of Traken) except for Serenity. After a time, Serenity formed a new empire under the same model, called the Benign Union.
Centuries later, the Sixth Doctor and Peri Brown visited the planet. Shortly after their arrival, Auga, Mura, and the hired safe-cracker Autolycus Ebbko, worked together to disconnect Prophecy's power supply, destroying it in the process. This woke Mallador, allowing the reawakening of the Melkur, who proceeded to attempt a take over of the planet. Meanwhile, Mura declared himself President of Serenity, before being killed by Mallador shortly after. Mallador's plans were halted by the Doctor's plan, and ultimately, Autolycus Ebbko's sacrifice.