PLEASE NOTE: This backstory is for reference and consistency only. We can reveal as much or as little of it as we want. But having it established ahead of time will give the stories a depth and consistency which will reflect well on the show.
What follows is a very brief history of the Transformers and the background which leads to the Beast Wars. Most of this information will be revealed in bits and pieces throughout the series and can also be used to pave the way for the return of the AutoBots and Decepticons if desired.
TIME: THE FAR FUTURE
In a galaxy far from our own shines the gleaming metallic world known as Cybertron. Its inhabitants are powerful, sentient Robots with their own advanced culture and civilization. These Robots fall into two classes: the Maximals - a race of beneficent Robots who use their powers to build and defend their world; and the Predacons, a race of feral conquerors who believe they alone have the right to rule Cybertron (and any other planet they can train their lasers on.)
Cybertron Mythology says both Maximal and Predacon evolved from two similar races who also fought for control of the planet, races known as AutoBots and Decepticons. For many years, the balance of power between these rivals stayed equal.
Then in another galaxy, on a far distant world known as Earth, an energy resource known as Energon was discovered. This resource was very powerful. From it great scientific advancements could be made and powerful weapons forged. It was obvious that whichever side controlled it would have an overwhelming advantage in the struggle. A band from each race was sent to this world to gather Energon and at the same time prevent the other side from obtaining it. The AutoBots won this struggle and the Decepticons went into hiding to plan for another day. A day which has not come... yet.
The original discovery of Earth by Cybertron came about through a Golden Disk, found in a probe sent by Earth's human inhabitants. (This was the Disk sent aboard the Voyager probe launched in 1977). This Disk resided in the Cybertron Hall of Knowledge, and was accorded the status of an ancient relic. From it Maximals learned much about the world on which their "ancestors" fought, a world no Cybertron has visited in centuries.
And then Megatron (the most feared leader of the Predacons) engineered the theft of the Disk. He and a band of his Predacon followers escaped Cybertron in a TransWarp ship, capable of traveling vast distances in both space and time. The Maximals responded quickly, a single exploration ship locking on to the Predacon's warp signature to follow them to Earth. And that's where our story begins.