The Golden Age, also known as the First Golden Age of Cybertron, was a period in Transformer history on their home-world of Cybertron when their world was rich in energy and the inhabitants were at peace with one another. This was a time before the political corruption, which ended with the beginning of the Great War.
The Golden Age of Cybertron began after the Quintessons were driven off-world. Free to govern themselves, the Cybertronians made use of the technological advances left behind by the Quintessons and began to consider expansion beyond their world. Space bridge technology was re-engineered and combined with cyber-forming tech to convert lifeless asteroids and planets into potentially inhabitable colony worlds.
Sentinel Zeta Prime, his council and scientists also conceived a way in which the Well of All Sparks could be duplicated on these colonies as well. In a ceremonial running of the torch, a spark of life from the Well was acquired and carried from the Well to the Space bridge of Iacon, across interplanetary distances to the first colony of Archon. Archon's governor, Metalhawk, dropped the torch into a duplicate Well crafted on Archon and it successfully ignited, ensuring that new Cybertronians could be born of the colony worlds as well.
The expansion was a great time of joy and prosperity among the Cybertronians, but it wasn't to last. The Keepers of the Well eventually reported that new life emerging from the Well was diminishing. It appeared that the Well's power was finite, and each Well across the colonies was still drawing from the same source. Without an endless supply of energon and life, Cybertron would have to be more frugal in establishing colonies until alternate sources of power could be conceived.
The Golden Age came to an end quickly once a mysterious Rust Plague began infecting transports among the colonies. The plague was universally infectious and fatal, and no cure could be found. Even testing proved difficult as the instruments corroded and the scientists died faster than results could be achieved. Quarantines began on infected worlds, followed by rioting, and death by fire for the lucky ones. Unable to reach a solution, Sentinel and the council made the fateful decision to destroy Cybertron's space bridge, permanently cutting the colonies off from home and each other, in order to prevent the Rust Plague from reaching Cybertron.
Cybertron now had greatly diminished resources (due to the duplicate Wells) and nothing to show for it, and the population was shellshocked by the loss of their brothers and sisters on the abandoned colonies. Unable to conceive of a new path for the future, Cybertron fell into a state of apathy and despair...and the Age of Rust set in.
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 caste system was established.
Cybertronian data cylinders were created during Cybertron's Golden Age to store the accumulated knowledge of the Transformers.