Pre-film history

Before becoming Prime, Optimus was part of one of many tribes that constituted Cybertronian society in eons past. At the time, Cybertron had no star to orbit and minimal resources, but Optimus would be recruited by Sentinel Prime to help him find the legendary AllSpark, the wellspring of all Cybertronian life. This endeavour was successful and Sentinel, Optimus and fellow recruit Megatron were all heralded as heroes for giving Cybertronians cause to unite. But Sentinel Prime had grown old and weary and refused to lead the Cybertronians, and, in confidence, he revealed to Optimus that he was a Prime, and that he ought to succeed him as leader. But Optimus could not believe he was a Prime. However, he believed by investigating Cybertron's history he could bring some of the good the Primes created back to the world. Sentinel redrew his plans for Cybertron, having Optimus lead the archaeological Science Division, while placing Megatron in charge of Cybertron's Defense Force.

For two generations, Optimus and Megatron ruled Cybertron together. The two personalities created a balance; Prime was fair while Megatron was firm. After an increase in malcontents disrupting Sentinel's order, Megatron intimidated Optimus into giving him supreme power in defence of the planet. When Lord Protector Megatron toured the excavation site near the AllSpark temple at Simfur, he and Optimus clashed over several issues. While Optimus wanted to take the investigation slowly, all Megatron cared about was whether the site contained power similar to the AllSpark. Optimus nettled Megatron when he reminded the Protector that the science sector was in charge of scientific and archaeological discoveries, and that the defence forces had a tendency to treat such discoveries as hostile, to which Megatron responded that if and when he was leader, he could make such decisions. When a mysterious relic was uncovered, Optimus disagreed with Megatron's order for it to be removed from the ground. Just as the two were about to launch into yet another argument, aliens previously encountered by Commander Starscream attacked Cybertron. Megatron blackmailed Optimus into moving the relic into his personal quarters by reminding the science leader that the science division would like to protect the only intact relic from harm.

Optimus ordered his science teams to help the survivors on both sides, in the hopes of finding out who was responsible and why they attacked. While he went off to find Megatron, he ordered the others to continue searching for survivors while Arcee examined the alien remains. Optimus was shocked and appalled when Megatron ordered him to marshal his forces for war. Optimus objected, as his science division was not trained for combat, but Megatron retorted that the scientists should have known that aliens were after the AllSpark. He endured Megatron's insane fury when he accused the Protector of betraying that upon which their society was built. Later, Optimus called upon a meeting with his science division to ask them to stay by his side and continue on with their mission of peaceful research, as they were protectors, not soldiers. While the aerial-based Cybertronians followed Megatron into space, Optimus confided in Prowl and Jazz that Megatron sought to divide their planet, and he asked the former for help breaking into the High Protector's personal quarters.

After noting that Megatron had restored the artifact to pristine condition, Optimus had to leave the military leader's quarters just before he returned. Back at Burthov, he came upon Ratchet, Arcee, and Elita-One scanning the pieces of the other artifacts. Arcee then discovered that the pieces all contained the same symbol on them, and that the same symbol was on Optimus' head. Ratchet declared that the symbol was proof of the Dynasty of Primes, and it indicated Optimus himself was a Prime. Ratchet and the other Autobots began to dub him "Optimus Prime", although a humble Optimus noted they did not know what it meant and for all they knew, he could just be from a line of record clerks. As they discussed the revelations, Prowl was forced by Megatron to arrest Optimus, but this turned out to be a trap to kill him. Optimus bested Starscream and blew up Metrotitan, while Megatron formed his new faction, the Decepticons. Optimus found Sentinel, Elita-One and Wheeljack under attack at the excavation site. He and Chromia rescued them and escaped through a tunnel. Optimus also informed Sentinel of the marking on his head that proved he was right all along: he was a Prime too.

With the foundation of the Decepticons, Cybertron became engulfed in devastating civil war which lasted for decades, leaving the planet in ruins and depleted of resources. In order to prevent the AllSpark from falling into Megatron's clutches, Optimus ordered his Autobots to jettison the cube into space, far from anyone's reach. Megatron took to the stars in search of the great relic, and though he managed to find the planet where the cube rested, he would lose power and find himself frozen in ice for centuries upon the very planet he had sought out. In the meantime, Optimus and the Autobots would also depart Cybertron to seek out the AllSpark, hoping to use its power to restore their world to life.

 

Transformers (2007)

 

By the year 2007 of the human Christian calendar, the Autobots had discovered that the AllSpark was on Earth. However, the Decepticons had already become aware of that fact and had planted several operatives on the planet to find both the cube and their fallen leader Megatron. Optimus sent his trusted scout Bumblebee to ascertain the AllSpark's precise location who discovered that a human boy known as Sam Witwicky may hold the key to finding it. Bumblebee discreetly kept watch over Sam while maintaining an Earth vehicle form, but had to reveal himself after the Decepticons attempted to capture the boy.

After revealing himself to Sam and his girlfriend Mikaela, Bumblebee signalled his Autobot comrades for a rendezvous. The Autobots made planetfall and Optimus Prime scanned a semi truck to use as his alternate form. He and the others assembled in the small town of Tranquillity where they met up with Bumblebee, Sam and Mikaela, introducing themselves and explaining their mission to find the AllSpark. Optimus informed Sam that the coordinates of the AllSpark had been imprinted upon the spectacles of his great-grandfather Archibald Witwicky, an explorer who had discovered Megatron buried in the Arctic Circle over a century ago. Optimus stated that he knew all of this by studying the internet and finding Sam's eBay account which showed the glasses and several of Archibald's other belongings up for auction.

Sam returned home to try and find the spectacles and the Autobots followed him. However, the presence of the Autobots on Earth had attracted the attention of the secret government agency Sector 7 who visited the Witwicky household and arrested Sam and Mikaela. The Autobots followed the Sector 7 agents and attempted to rescue the kids, but their interference was met with aggressive force. Despite Optimus' efforts, both Sam and Mikaela were taken into custody and Bumblebee was captured by Sector 7 and subjected to painful experiments.

Later on, Optimus, Jazz, Ironhide and Ratchet followed Sam's captors to their base at Hoover Dam where it was discovered that both the AllSpark and the frozen body of Megatron were being kept. The miniature Decepticon Frenzy had infiltrated the base and sabotaged the cryogenic facilities that kept Megatron inert, allowing the Decepticon warlord to thaw and re-awaken. The base was evacuated as Megatron thawed out and Sam and Bumblebee took the AllSpark (shrunken down to a more compact size) to Mission City. The Decepticons pursued and Optimus personally engaged the Decepticon Bonecrusher as he closed in on Sam and Bumblebee on the highway. After a brief, but intense fight between the two alien robots, Optimus killed Bonecrusher by severing the Decepticon's head with his energon sword.

With both Transformer factions meeting in Mission City, a ferocious battle erupted with the human residents of the city caught in the middle. Megatron soon arrived and pursued Sam who clung to the AllSpark like his life depended on it (which it did). Optimus intervened and attempted to settle the score with Megatron, but it seemed that Megatron's horrific strength and tenacity had not diminished at all after spending centuries frozen in ice. In order to deny Megatron victory, Optimus was prepared to sacrifice himself and urged Sam to thrust the AllSpark cube into his chest, expecting its raw power to burn out his spark. Sam, however, was unwilling to let Optimus make such a sacrifice and instead he gave Megatron what he wanted... so to speak. Sam collided the AllSpark with Megatron's own spark core, causing the Decepticon leader's spark to burn out and destroying the cube.

Optimus remorsefully bid farewell to his former brother, telling Megatron that he had left Prime no choice. Following the Battle of Mission City, Megatron and the other fallen Decepticons were taken by the US military and their bodies were cast into the Laurentian Abyss, the deepest of Earth's oceans, where they would be entombed forever. The Autobots had won, but without the AllSpark they had no hope of reviving Cybertron, and so they were granted refugee status by the US government and permitted to stay on Earth. As the Autobots rested following the battle, Optimus Prime transmitted a message to the stars calling for any surviving Autobots to come to Earth.

 

Revenge Of The Fallen

Two years following the destruction of the AllSpark, Optimus Prime and the Autobots had established an alliance with the US military, forming a human/Autobot special ops force called NEST. NEST was tasked with tracking down and eliminating any Decepticons remaining on Earth, and following a successful operation in Shanghai, China, it became clear that the Decepticons were far from finished. A foreboding message from a Decepticon prior to his execution warned that "The Fallen will rise again".

The Fallen - a former Prime and the original Decepticon according to Transformer legend - had awoken from an ages long period of isolation and was now coordinating Decepticon activity on Earth. He sought to revive his slain disciple Megatron and was able to achieve this objective by having his minions steal a remaining fragment of the AllSpark from human custody. Using the fragment, the Decepticons resurrected Megatron and the Decepticon leader plotted with his ancient master to capture Sam Witwicky, the boy who was responsible for destroying the AllSpark. Sam had held on to a small fragment of the cube which had imprinted its vast knowledge into the boy's mind, giving the Decepticons cause to believe that he may be able to locate the Matrix of Leadership, an ancient Transformer relic key to reactivating a machine that the Fallen had built centuries ago called the Sun Harvester which would be used to destroy Earth's sun and convert it into energon. However, one obstacle stood in the way of the Fallen's plan: Optimus Prime, the last of the Primes.

 

In order to lure Optimus into a trap, the Decepticons abducted Sam, his girlfriend Mikaela and their mutual acquaintace Leo Spitz from their college campus. Before Megatron could dissect Sam's brain, the Autobots tracked them down and attempted to rescue the kids. The Decepticons pursued Sam into the forest and Optimus bravely tried to fend off Megatron, Starscream and Grindor all by himself. The battle did not bode well for the Autobot leader as he was badly beaten before ultimately being impaled and shot through the back by Megatron.

With Optimus Prime dead, the Fallen rallied his forces and they issued an ultimatum to the people of Earth, threatening to destroy the whole planet if Sam was not surrendered to them. Sam, Mikaela and Leo, along with Autobots Bumblebee, Mudflap, Skids and former Sector 7 agent Simmons, followed information offered to them by Decepticon traitor Wheelie and discovered that an ancient Cybertronian Seeker known as Jetfire had been living in exile on Earth for centuries. The elderly, rusty Jetfire informed the group about the Fallen and the Dynasty of Primes, stating that they had built the Sun Harvester on Earth in ancient times and that the Matrix of Leadership had been hidden away in the deserts of Egypt.

After being transported to Egypt, the group sought out the Tomb of the Primes and found the Matrix. NEST had located the Sun Harvester and were en route to rendezvous with Sam carrying Optimus' body in tow, but the Decepticons had found the device as well and a great battle ensued. Against all odds and almost at the cost of his life, Sam was able to reach Optimus and fused the Matrix with his spark core. Optimus was restored to life and his body enhanced with new armour, weapons and flight tech offered by Jetfire at the cost of his life. With his newfound power, Prime decimated the remaining Decepticons, destroyed the Sun Harvester and finally killed the Fallen by ripping him apart.

 

Dark Of The Moon

Optimus, now with a trailer that transforms into a weapons pack that can also acts as flight gear, travels to Chernobyl with NEST where they retrieve a mysterious engine part before coming under attack by Decepticon assassin Shockwave and his pet Driller robot. Though he successfully fends off Shockwave, Optimus is shocked to discover that the engine part is of Cybertronian origin. The device originally was part of the Ark, an Autobot vessel commanded by Sentinel Prime during the final days of the Cybertronian Civil War.

Some time after the engine part's discovery, Charlotte Manning - director of NEST - reveals that a small number of humans have been aware of the existence of Cybertronians for some time, ever since the Apollo 11 moon landing. The Ark is revealed to still be on the moon and so Optimus leads a NEST team there to find the ship and recover its precious cargo. They find Sentinel Prime in stasis lock and recover five of the Space Bridge Pillars that had been stored aboard the ship, including the Control Pillar.

Upon their return to Earth, the pillars are put into a vault under the human's control and Optimus prepares to use the Matrix of Leadership to revive Sentinel. After the arrival of Sam Witwicky, Optimus successfully revives Sentinel who initially attacks him, before calming down after learning where they are. The two then explain to the humans about the space bridge and the threat that would be posed if the Decepticons learned of it and got the pillars.

Afterwards, Optimus takes Sentinel for a drive to show him some of the planet. Sentinel is impressed and Optimus offers him the Matrix of Leadership after lamenting what could've happened if Sentinel had led the final battle of the war. Sentinel refuses the Matrix and tells Optimus that he is now the teacher, not him.

Later, Optimus rushes back to the base after Sam discovers what the Decepticons are up to, but is too late as Sentinel has revealed his true colours, murdered Ironhide, and taken the pillars.

At the National Mall, Optimus pleads with Sentinel, who is using the space bridge to bring an army of hundreds of Decepticons to Earth, to stop. When that fails, Optimus attacks Sentinel, but Optimus proves to be no match for the former leader. Sentinel pins him down and explains that he did what he did to save Cybertron before leaving, telling Optimus that he's lucky he didn't kill him and that he will one day understand.

After Sentinel makes an ultimatum to the United Nations, the Autobots are ordered to be exiled from the planet. Near the Xantium, Optimus meets with a deeply saddened Sam who tries to get him to stay. Optimus informs Sam that they have to go and gives some words of wisdom to his old friend about not losing faith in yourself and that the war is the humans now. Sam, under threat against his girlfriend, tries to find out the Autobots plans, subtly warning Optimus of the truth by telling him that no other human will ever know. Optimus tells him that there is no plan and tells Bumblebee to make his goodbye quick. Optimus and the other Autobots are apparently killed when the Xantium is destroyed by Starscream.

In truth, Optimus and the others abandoned the Xantium before its destruction and they head to Chicago to fight the Decepticons with the element of surprise. Optimus arrives just in time to shoot down a Decepticon fighter and save Sam, Epps and their team and orders the Wreckers to kill the pilot. After making a speech about taking the fight to the Decepticons, Sam and Bumblebee take the downed fighter to rescue Carly and succeed, killing Laserbeak in the process and hooking up with Optimus and the rest of the Autobots afterwards.

Optimus and the other Autobots head further into the city to open a way for Sam, Epps and their team to make their way to a building where they will attempt to shoot down the Control Pillar. Along the way, Shockwave and his Driller attack, separating Optimus from his trailer. After linking up with the humans in a building, Optimus heads out to retrieve his trailer, needing the weapons and flight gear it contains.

Optimus successfully retrieves his trailer and flies in, in time to attack the Driller and save the team from death. Optimus shoots the Driller multiple times before crashing through it, breaking it in half and killing it. Optimus lands on top of a crane where an enraged Shockwave blasts him, causing him to get tangled up in cables. Optimus is spotted by the Wreckers who quickly climb up to cut him free.

The Wreckers eventually cut Optimus free and he flies back into battle, killing several Decepticons before attacking Shockwave who is fighting NEST. Optimus slashes Shockwave across the torso with bladed knuckles and rips his eye out, killing him. Seeing an opportunity, Optimus uses Shockwave's cannon to blast the Control Pillar from the building its on, temporarily deactivating the space bridge that is bringing Cybertron to Earth. Optimus challenges an enraged Sentinel to battle and battles him using a battle-axe and his sword. Prime has the upper hand, until Sentinel calls upon the Decepticon figher ships to attack Optimus. Optimus is forced to turn his attention to the Decepticon fighters and shoot at them with his Ion Blaster. After the fighters are destroyed, Optimus pursues the retreating Sentinel.

Optimus quickly catches up with Sentinel on a bridge and re-engages him. Optimus holds his own, until Sentinel cuts off his right arm and knocks him down. As Sentinel is about to kill Optimus, he is attacked and grievously injured by Megatron, who had been convinced by Carly that Megatron that he would be working for Sentinel, and not with him as Megatron wanted. At the same time, after Sam kills Dylan Gould, who reactivated the space bridge, Bumblebee and Ratchet destroy the Control Pillar, causing all the Decepticon ships to get sucked up into Cybertron which collapses upon itself and is destroyed.

With no army left to command, Megatron confronts Optimus one last time. Even with only one arm, Optimus is still too much for Megatron and decapitates him with his energy axe, seemingly ending his reign of terror once and for all. With bitter regret, Optimus then turns his attention to the wounded Sentinel, stating that he was a traitor to himself as well as their world. Optimus then executes Sentinel with Megatron's fusion shotgun.