Precursor World

The Precursor World (前史世界 Zenshi Sekai) is precisely what it says on the tin: the reality immediately prior to the "Known World" of Optimus Prime, Megatron, and friends in the Japanese Generation 1 cartoon continuity. Try not to think about it too hard.

Fiction

Generations Selects Special Comic

In the beginning, there were seven universes, each protected by its own colored order of the Primus Vanguard. When the Specters threatened the universes, the leaders of the Primal Vanguard decided to unleash the full light of their matrices to extinguish all shadows. This had the secondary effect of merging the seven universes into one, peaceful space. Finale Part 1

Notes

• The Japanese term Zenshi Sekai more formally means "Prehistoric World". This is a label that exists in contrast with Seishi Sekai (正史世界, lit. "Official History World"), which we've translated as "Known World". Those two terms are meant to emphasize the fact that this world exists prior to all history of the G1 World that is known to its characters and the reader.