In Transformers G1 (The original 1984 series) the war on Cybertron was described in Episode 38 "Desertion of the Dinobots, Part 2" like this:
Millions of years ago, Cybertron was a planet of peace...until the
Decepticons, lusting for power, began a terrible war. Not designed for
combat, the Autobots were overwhelmed and subjugated by their evil
opponents. While many Autobots fled Cybertron, a few valiant survivors
devised new tactics and launched a counter-offensive on their
arch-foes. And thus began a terrible series of wars. Many times, both
sides have claimed victory, but this has been short-lived, for the
Autobots have overthrown Decepticon tyrants, and, likewise, Decepticon
treachery has toppled many a peaceful Autobot ruler. And to this day,
the war rages on.
The Quintessons made the Transformers originally, though they didn't transform then, and the Transformers eventually turned on the Quintessons and drove them off the planet.
After the slaves drove the Quintessons away from Cybertron, peace
reigned. However, the division between consumer goods and military
hardware was becoming acute, as the two groups had even named
themselves differently: The consumer goods robots called themselves
Autobots, and the military hardware robots were known as Decepticons.
While the Autobots preferred a peaceful existence, the Decepticons
wanted conquest. For a time, the Decepticons succeeded.
The Autobots then developed transformation and the guardian robots to defend themselves, and that was known as the 'Golden Age of Cybertron':
The Matrix was already in existence at this point, apparently being passed from one Autobot leader to the next, as is the practice today.
The Autobots couldn't match the brute strength of the Decepticons, so
they turned to stealth, learning the art of transformation. Using this
new technology, they defeated the Decepticons and ruled for many
centuries in a "Golden Age." Peace was kept with the use of Guardian
robots (presumably based upon the Quintessons' Dark Guardians),
sentinels that protected cities, quelled uprisings, and generally did
the dirty work of war. However, the Decepticons eventually learned to
transform and also developed some form of anti-gravity that allowed
them to fly without the use of jets. They also built a powerful leader
for themselves: Megatron.