Prime is the rank of highest possible distinction on Cybertron. The original had their powers flowing through their very CNA. Currently, their powers are something bestowed only to those carrying the Matrix of Leadership containing the will of Primus.
Following the War of the Primes, the Covenant of Primus decreed there would only be one Prime ruling Cybertron at a time. It was technically Primus's right to appoint the Prime and bestow them the Matrix but gradually his children became more and more ignorant of his presence as well as that of his brother Unicron. It seems Sentinel Zeta Prime was the only Prime between the Age of the Primes and Optimus Prime as he fought off the Quintessons, established the Golden Age and tried to combat its decline by establishing the Caste System to Alpha Trion's displeasure. Sentinel was unworthy of the Matrix and the Core said it was only after his death that Optimus could receive it as being a Prime was not a status Trion or the Autobot High Council could grant. The civil war began and continued as Megatron and Starscream both wanted to be Prime and bear the Matrix.
The High Council declares they exist to choose the Primes, and seemingly referencing the Thirteen, note they have watched as many Primes fell to their greed and pride. In the war of cybertron TV series. The matrix chooses the prime. Optimus became a prime after Alpha Trion gathered Megatron, Ultra Magnus, And Optimus So the matrix can choose it's prime
Megatron traveled to Cybertron with Dreadwing to visit a tomb known to hold the remains of a Prime. He severed the arm of the Prime and attached it to his own body to gain control of the Forge of Solus Prime. With the Forge, he crafted the Dark Star Saber.
As he prepared to sacrifice himself to restore the AllSpark to the core of Cybertron, Optimus Prime told his team members that, although they may not technically be Primes, he believed that they had each demonstrated the worth of a Prime in the recent conflict against Unicron.
The Thirteen Primes had a personal mystic plane of existence known as the Realm of the Primes. After becoming one with the AllSpark, Optimus Prime trained here in preparation for a coming threat to both Earth and Cybertron.
When the return of Megatronus came, Micronus Prime took Optimus to consult the other Primes on their next course of action. Though the other Primes thought that Optimus's training was not complete, Optimus convinced them to give him their power and send him to Earth to deal with Megatronus immediately.
- Prima (presumed deceased)
- Megatronus (presumed deceased)
- Alpha Trion (deceased)
- Vector Prime (unknown)
- Quintus Prime (presumed deceased)
- Nexus Prime (alive)
- Solus Prime (deceased)
- Liege Maximo (deceased)
- Alchemist Prime (unknown)
- Amalgamous Prime (unknown)
- Onyx Prime (merged with Primus)
- Micronus Prime (in the Realm of the Primes)
- Optimus Prime (alive)
- Sentinel Zeta Prime (deceased)
- Before the line ended Smokescreen was Optimus and Alpha Trion's first choice to inherit the Matrix while Smokescreen himself felt Bumblebee was better suited.
- When someone is selected as a Prime they have the title as a last name such as Orion Pax when he was selected.
- There is a misconception that the Matrix is a requirement despite it being said in War for Cybertron that it was the High Council's job in choosing a Prime to lead. This was how Optimus and Sentinel Zeta received their ranks.
- Optimus said Team Prime acted like true Primes with or without the Matrix as his last words before entering Cybertron's core.