Golden Age
The Golden Age, also known as the First Golden Age of Cybertron, was a period in Transformer history on their homeworld of Cybertron when their world was rich in energy and the inhabitants were at peace with one another. It ended with the beginning of the Great War.
Fiction
Generation 1 cartoon
Nine million years ago, Cybertron was at peace until Megatron led his newly formed Decepticon army against the peaceful Autobots which began the very, very, very long series of wars that resulted in a broken planet. War Dawn
Cybertron entered into a new Golden Age when the Plasma Energy Chamber was used to repower the planet which was now in the hands of the peaceful Autobots, who would probably use it a lot better than the Decepticons did.... The Rebirth, Part 3
Robots in Disguise
The O-Parts, or anything like them, have not been seen since the Golden Age. The Ultimate Robot Warrior
Prime
Sentinel Prime fended off a Quintesson invasion and oversaw the construction of the Hydrax Plateau spaceport, the Moonbases, Trypticon, the space bridges, and the colonies. The Golden Age drew to a close as the space bridges grew less reliable, contact with the colonies was lost and the establishment of the caste system. Exodus: The Official History of the War for Cybertron

