Optimus Prime is the leader of the Autobots from the planet of Cybertron. At some point, he was a member of an order of Cybertronian knights who were dedicated to exploring the universe but he left to focus on becoming a Prime, leaving his sword and shield behind in the Knights' Temenos. Optimus and his Autobots left Cybertron after losing the Allspark. The Autobots have now found their way to Earth and the war continues there. He's now been brainwashed by Quintessa, turned into Nemesis Prime.