Optimus Prime (Transformers Cinematic Universe)

"Fate rarely calls upon us at a moment of our choosing"

- Optimus Prime

"Were we so different? They're a young species. They have much to learn. But I've seen goodness in them. Freedom is the right of all sentient beings. You all know there's only one way to end this war: we must destroy the Cube."

- Optimus after Ironhide asks him why they are defending the human race

"Before time began, there was the Cube. We know not where it comes from, only that it holds the power to create worlds and fill them with life. That is how our race was born. For a time, we lived in harmony. But like all great power, some wanted it for good, others for evil. And so began the war. A war that ravaged our planet until it was consumed by death, and the Cube was lost to the far reaches of space. We scattered across the galaxy, hoping to find it and rebuild our home. Searching every star, every world. And just when all hope seemed lost, message of a new discovery drew us to an unknown planet called... Earth. But we were already too late."

- Prime's opening narration in the 2007 first movie "it's you and me ,Megatron ,one shall stand ,one shall fall!"

- Optimus to his arch-nemesis Megatron during their final battle in the 2007 movie  

Optimus Prime is the main protagonist of the live-action Transformers film series, appearing in the first film, Revenge of the Fallen, Dark of the Moon, and Age of Extinction sharing the role with Sam Witwicky and Cade Yeager. Originally a peaceful Cybertronian scientist and the very last Prime of the Dynasty, Optimus and his team of scientists were studying the mysterious Allspark until they were betrayed by their security unit, the Decepticons, and its now corrupted power hungry leader, Megatron. Naming his squad of scientists Autobots, he used his team to fight the tyrannical Decepticons in order to stop them from getting the Allspark's awesome power. He is based off his original incarnation with the same name.

He is voiced by Peter Cullen who also voiced the character in the original.

Transformers (2007)
Optimus leads his Autobots to go against the Decepticons who are searching for the Allspark so they can take over Cybertron while the Autobots search for it to rebuild it. The Allspark was eventually lost and Megatron followed it to earth.

He then discovered that the coordinates of the Allspark's location were imprinted in Captain Archibald Witwicky's glasses when the Captain found a frozen Megatron and accidentally activated his navigational system. He also discovered that the glasses is in the hands of Witwicky's grandson, Sam.

Optimus then have Bumblebee head down to Earth and find Sam before the Decepticons can do so.

Transformers: Revenge of the Fallen
Optimus Prime still serves as the main protagonist of the film, at the end of the film, he ends up killing The Fallen by using The Fallen's shock-spear.

Transformers: Dark of the Moon
Optimus Prime serves as the main protagonist of the film, at the end of the film, he ends up killing Megatron by cutting his head off with a axe and killing Sentinel Prime by shooting his head and his chest using Megatron's shotgun.

Transformers: Age of Extinction
In the fourth film of the series, Prime returns as the main protagonist alongside the other Autobots, however he is alot more vengeful and destructive than in the previous films, this is mainly due to humanity betraying him. Together, they are not only protecting on Earth, also Cade Yeager, his daughter Tessa and her boyfriend Shane Dyson from Harold Attinger and Lockdown whom planned to destroy the entire transformers in order to "protect" (destroy) the world from them with a alien special weapon called "The Seed". With a group of legendary knights called Dinobots led by Grimlock and also to fight against Megatron again, now known as Galvatron.

Transformers: The Last Knight
In the fifth film, Optimus is still searching for his creators and will be reprogrammed by an unknown villain.

Trivia

 * Optimus in this version has tendency to strike his foe's face.