Birth Of Transformers
Before the dawn of time, the One – also known as the Source and the sentient core of the Universe – is an extra-dimensional entity in whom order and chaos exist in perfect harmony.
The One created the astral being Unicron, which was then split into half. One remained Unicron while the other became Primus.
While Primus embodied order and justice upon his birth, Unicron was left with chaos and evil, which gave him a sense of fallen existence.
Thus began the long-time battle between the two. Later their rampaging feud brought them to the physical world where they were accidentially trapped inside metallic elements – which eventually paved their way to become gigantic robots.
Then Primus turned into the planet Cybertron and created the original 13 Primes, who were each infused with a fragment of Primus' life essence known as the Autobot Matrix Of Leadership, to help himself in his war against Unicron.
When the war was over, Unicron was sucked into a black hole and vanished from reality until Transformers The Movie in 1986.
Meanwhile, Primus entered his eons-long slumber while the original 13 Primes began to create other robots and thus began the Transformers story.