Cybertronian History
The 13 Primes:
In the late 1800s, the ruling system began to fall apart to be replaced by the primary system due to the discovery of the legendary and ancient Matrix of Leadership. The first ever bearer of the Matrix of Leadership recorded in history, Optimus Prime I chose 12 more people to stand with and help him carry the burden of being a Prime. Optimus Prime also gave them each the title of prime and together, they were the 13 Primes.
The 13 Primes are as follows: Optimus Prime, Megatronus Prime, Prima, Solus Prime, Alphatrion Prime, Onyx Prime, Micronus Prime, Amalgamus Prime, Vector Prime, Alchemist Prime, Nexus Prime, Quintus Prime and Liege Maximo.
Primus and Unicron:
Primus and Unicron served as the mentors of the 13 Primes until Unicron, in a thirst for power, abandoned Primus and the 13 Primes to go on a separate, darker path.
The first Battle with Unicron:
The 13 Primes along with Primus, fought against Unicron and his army to defeat them. Unicron failed to accomplish his evil goals and therefore, retreated.
The Prime Wars:
Unicron manipulated Liege Maximo who, in turn manipulated Megatronus Prime to turn against the Primes and kill Solus Prime. This led to conflict within the Primes which ended with Megatronus and Liege Maximo in prison.
Redemption of Megatronus and the escape of Liege Maximo (forgotten piece of history):
10 years later, Megatronus confessed it was in fact, Liege Maximo who had manipulated him but before the Primes could do anything, Liege Maximo escaped. At the same time, Primus unfortunately passed away.
The second and last battle with Unicron:
Liege Maximo redeemed himself in the final battle with Unicron by sacrificing himself and defeating Unicron.
Primary System (renewed):
After this whole affair, future generations decided to give the Matrix of Leadership to one person so that the person could become a Prime but there were still 12 people required to guide the chosen Prime and those 12 people were referred to as the High Council. Also, the prime of Iacon only was given the Matrix of Leadership and in other countries, the Primes were voted for.
Beginning of the Caste System:
This system was introduced by Exarchon as a means to condemn all of Cybertron to slavery.
First Cybertronian World War:
This war was fought against Exarchon's system. Nominus Prime was the leader of the faction against Exarchon. His faction was the Autobots. Nominus Prime was the winner of this war and was also the bearer of the Matrix of Leadership during that time.
Author's Note: You need to know this before you read the story. Anyway, Primus and Unicron are normal Cybertronians and not giant sized planets.