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Sentinel Prime
Transformers character
First appearance Transformers Generation 1
Voiced by Jack Angel
Brian Dobson
Townsend Coleman
Leonard Nimoy
Troy Baker
{Japanese) Takurō Kitagawa
Shimizu Toshitaka
Junichi Suwabe
Aliases Sentinel Major, Sentinel Minor, Infinitus, Magnus
Affiliation Autobot
Partner Optimus Prime (Successor)
Megatron (Betrayer)
Quintessa (Creator)
Hot Shot
Liege Maximo
Kreon Sentinel Prime
Alternate modes Cybertronian Train
Cybertronian Space Shuttle
Cybertronian Dune Buggy
Cybertronian Truck
Snowplow Truck
Rosenbauer Panther fire engine
Cybertronian fire engine
Cybertronian Car

Sentinel Prime is the name of several fictional characters in the various Transformers series in the Transformers robot superhero franchise.

First mention of Sentinel Prime was in issue #65 of the US Marvel Comics Transformers series, where he was mentioned to hold the Autobot Matrix of Leadership before Optimus Prime. Sentinel Prime is One of the members of the Dynasty of Primes and dedicated as the leader of the Autobots and has since appeared in a variety of forms as either Optimus Prime's mentor or friend.

Fun Publications has also had a character in their comic called Sentinel Major, who is based on the Transformers Animated version of Sentinel Prime. He is also the main antagonist in the film Transformers: Dark of the Moon, where he betrays the Autobots and later Megatron for his own personal interests. His original Generation 1 incarnation was later reimagined by IDW Publishing as a similar fallen figure, perhaps in lieu of his movie counterpart.

Transformers: Generation 1

Sentinel Prime (sometimes formerly called Sentinel Major and Infinitus) is an Autobot leader from the Generation 1 continuity family. Sentinel Prime is an imposing figure, standing head and shoulders over the average Autobot. Bristling with some of the most heavy-duty weapons and armor available to the Autobot army has instilled in Sentinel Prime a supreme confidence in his own abilities as both a leader and a fighter. Unfortunately such pride usually precedes a fall, and there will always be someone out there keen to prove a point, or who merely sees Sentinel Prime as an obstacle on the path to a bigger destiny. Sentinel Prime is often portrayed as Optimus Prime's immediate predecessor as Autobot leader.

Animated series

Sentinel Major was originally one of the Quintessons' slave robots on Cybertron around twelve million years ago. Unusual among his consumer goods brethren, Sentinel Major was equipped for combat and was forced to participate in gladiatorial games for the Quintessons' amusement, wielding a spiked ball-and-chain weapon and a tire-shaped shield. He was once defeated in battle by Prima, who attacked their Quintesson masters when their match was over, only to be destroyed himself.

Subsequently, the consumer goods robots rose up against the Quintessons in a rebellion that ultimately forced the aliens off the planet. Sentinel Major survived this clash, but he and the rest of his race—now dubbed "Autobots"—were robbed of any chance of peace when the military hardware robots, now known as "Decepticons", set their sights on conquering Cybertron for themselves. Two Autobot leaders fell during the war that ensued, and Sentinel Major inherited the Matrix of Leadership and became Sentinel Prime, leader of the Autobots. Under his leadership, the Autobots realized that they would never be able to defeat the Decepticons with firepower, and they turned instead to stealth, reconfiguring their bodies to be able to transform into other forms. With the power of his new ability, Sentinel Prime defeated the Decepticons' leader, and the Autobots won the war.

The ensuing period of peace was known as the Golden Age of Cybertron, but, around nine million years BC, the Decepticon threat re-emerged when they too adopted transformation, and coupled it with robot-mode flight powers. One of the first of this new breed of Decepticons, the malevolent Megatron, killed Sentinel Prime in combat. As he died, the dying Sentinel Prime handed off the Matrix to Alpha Trion, who kept it safe until the emergence of the next Autobot leader, Optimus Prime. When Rodimus Prime journeyed into the Matrix in 2005, Sentinel Prime was the sixth guide he encountered. Sentinel Prime recounted the development of transformation, the Autobot victory in the war and the rise of Megatron.

Transformers: Armada

A character named Sentinel Minor appears in the Transformers: Armada episode "Past". This version of Sentinel was the platoon commander of Hot Shot's military unit during the earlier years of the war on Cybertron. Sentinel Minor was known simply as the "Arrogant Autobot officer" for years until finally being given a name in the Facebook version of Ask Vector Prime. The name is likely a reference to Animated Sentinel Prime. Like many Armada generics, Sentinel uses a recolored Generation 1 character model. In this case, it's a recolored animation model of Sureshot—but the more toy-based Headmasters model rather than the American comic model.

Animated series

During a major battle, Wheeljack had become trapped under some rubble in the middle of an inferno. Hot Shot could not free his friend and left, promising to return with help. However, Sentinel Minor and his subordinate refused to help Wheeljack, saying that the flames were too hot to enter. Hot Shot objected and attempted to run back in, only to be obstructed by his fellow soldier and struck down by his officer. Sentinel cited that they could not risk the unit to save only one 'bot. Hot Shot eventually got up, and despite the warnings of a court-martial, raced back into the flames hoping to save his friend. Hot Shot failed and fainted in the fires. Sentinel pulled him out, but Hot Shot was put under Optimus Prime's direct command after this event.

Transformers Animated

In the series Transformers Animated, Sentinel Prime is a hotheaded member of the Cybertron Elite Guard. Sentinel's main weapon is a shield called the Skyboom Shield, that is able to generate force fields and can be used offensively when thrown. He also wields a laser lance, and can activate a battle mask when needed.

In December 2007, drawings were leaked on the internet of Sentinel Prime's vehicle appearance in the Transformers Animated television series. He turns into a snow plow truck. Derrick Wyatt stated that the character was originally meant to be named Rodimus Prime, after Optimus Prime's G1 Successor. However, the idea of Rodimus being portrayed as arrogant and rude was dropped in favor of Sentinel Prime. An interesting note is that Sentinel's robot mode bears a strong resemblance to The Tick, which was a result of Townsend Coleman (the voice of the animated Tick) being cast in the role.

Animated series

Once known as Sentinel Minor, he was the drill sergeant training Bumblebee, Wasp, Bulkhead, Longarm and Ironhide, who were recruited into the Autobots. When it appeared that Wasp was a secret Decepticon spy Sentinel Prime arrested the innocent Autobot, not realizing it was Longarm who was the traitor. It was also revealed that he didn't like Ultra Magnus because of the recruits he is forced to train and was friends with Cliffjumper. Sentinel Prime and Optimus Prime have been friends since they attended the Autobot Academy together with Elita-1 (whom Sentinel had feelings for) as seen in a flashback in "Along Came a Spider."

Things changed when Sentinel brought the others to an organic planet to find a lost Decepticon warship, only to be attacked by giant alien spiders that inhabited the planet and the ship exploded during the confrontation. In spite of Sentinel's pleas, Optimus was forced to leave Elita-1 on the notion that she was killed in the explosion, both unaware of her transformation to Blackarachnia. Sentinel got so angry that he completely blamed Optimus for the loss of Elita-1, even though it was his idea to come to this planet. Since then, Sentinel never forgave Optimus for the incident and developed a racial fear of organics, believing that they'd all be the same as those spiders. During the inquiry, in which both he and Optimus were accused of going to an unauthorized organic planet, Optimus took full responsibility as the senior cadet for Elita-1's apparent death, which led to his expulsion from Autobot Academy and barred from assuming any Elite Guard position. Sentinel on the other hand, who denied being the one who caused the chain of events, wasn't punished for his involvement and later rose to prominence in the Elite Guard. At the beginning of the series, when Optimus tried to contact Autobot High Command, Sentinel refused to allow him to see Ultra Magnus until Optimus showed him the Allspark.

Sentinel Prime (alongside Ultra Magnus and Jazz) arrived on Earth to look for the Allspark. He had Prime's crew "decontaminated" from organic infestation. He didn't believe Prime's stories about the Allspark being destroyed or their encounters with Decepticons. He did end up attempting to fend off the Dinobots on Dinobot Island when he provoked them. After the incident at one of the factories owned by Isaac Sumdac (in which the fragment of the Allspark was the cause of this), Sentinel Prime threatened to make sure Optimus was charged with treason for destroying the Allspark, however Optimus had grown tired of Sentinel's arrogance and reminded him despite being an Elite Guard washout, he and Sentinel still shared equal rank and told him he was on "his turf now".

Ultra Magnus stated to Sentinel Prime that he can learn a lot of things from Optimus Prime, such as loyalty. In "Return of The Headmaster", Sentinel Prime got a lesson in humility after his body was taken by the Headmaster and he was forced into a partnership with Optimus to get it back. In order to improve morale, Sentinel tried to force Optimus Prime to declare that they hadn't encountered any Decepticons, but Optimus refused to do so. Sentinel then tried to bribe him with re-entry into the Elite Guard; when he didn't comply, he placed Optimus into custody. Sentinel later refused to believe that Ultra Magnus and Jazz were walking into a Decepticon trap, so Optimus tricked him into a pair of stasis cuffs in order to save the day. Sentinel soon learned Prime was telling the truth when Starscream fell from the sky. It was shown that he choked up under pressure and fear at the sight of a Decepticon.

In "Five Servos of Doom" he had seemingly captured Sunstorm, Blitzwing, Lugnut, and Swindle (though he admitted that since Swindle was trapped in vehicle mode he simply had to pay a fine and have him towed) by himself. Optimus, Jazz, and Prowl were extremely doubtful that he could have accomplished such feats, and set out to find how he did it. After following Sentinel Prime it was revealed that it was Lockdown who was capturing the Decpticons and trading them to Sentinel for Autobot upgrades. After being betrayed by Lockdown, who was working for Ramjet, Sentinel ended up becoming the Clone's hostage and shield, taking most of the Autobots attacks on himself and ending up face-first in the ground. Optimus covered for Sentinel when reporting to Cybertron, giving credit for the captures to Prowl, but he assured Sentinel that they would "talk it out" when the crisis was over.

In "Predacons Rising", Bumblebee, Jetfire, Jetstorm, Optimus Prime and Sentinel Prime chased Wasp; Sentinel believed that Wasp knew about Ultra Magnus's attacked, but lost him to Swoop while bickering about what to do with him. Following Swoop to Dinobot Island, Sentinel encountered Blackarachnia, learning the truth about what happened to her as Elita-1. Disgusted by what had happened to her, Sentinel refused to accept her as the Elita he knew and attempts to kill her before Wasp (newly changed into Waspinator) intervened. After Blackarachnia sacrificed herself to save the Autobots from a transwarp energy-overloaded Waspinator, Sentinel expressed regret for what had happened to her, even taking blame for what had happened that day, and burying the hatchet with Optimus. Sentinel and the Elite Guard returned to Cybertron soon after, with Sentinel having to take command in the wake of Shockwave's attack on Ultra Magnus.

In "Decepticon Air", Sentinel interrogated the captive Decepticons for information concerning the recent Space Bridge attacks. Sentinel's ego and recent rise in ranks gets the better of him. In order to get back to Cybertron quickly so he can take over as the new Magnus, he ordered Jazz to take the ship through an ion storm. The resulting energy discharges free Swindle from his locked vehicle mode, which allowed the other Decepticons to take over the ship. Sentinel was forced to call for help, specifically for Optimus with a secret Academy code. The Decepticons were defeated and recaptured, though Swindle and Lugnut escaped. In gratitude, Sentinel offered Optimus the Eite Guard position he would have to vacate in order to become Magnus, but Optimus declined his offer, stating that there was still work to do on Earth. So he drops him off back to Earth, salutes to him then departs. On his return to Cybertron, Sentinel paraded the remaining Decepticons in front of the citizens before assuming command as the new Magnus.

In "This is Why I Hate Machines", Sentinel had apparently spread his hatred and fear of organics to all of Cybertron, as when Ratchet and police captain Fanzone arrive, nearly every Autobot who sees Fanzone is terrified. When Omega Supreme (piloted by Megatron, Starscream and Lugnut) transwarped to Cybertron, Sentinel ordered a full-scale assault on the colossus, only for the Autobot Council to deliberate whether to strike and possibly destroy Cybertron with it (as Ratchet had pointed out) or possibly miss a chance to end the Decepticon threat. Sentinel ignored the council's wishes to wait and prepared for a strike, claiming that as acting Magnus, he had to be prepared. However, Sentinel is chastised by Alpha Trion and Perceptor after Omega transwarped elsewhere before getting hit by the attack. When Ratchet and Fanzone returned to Earth with the Magnus hammer, Jazz pretended to give pursuit, but instead chose to stay with the Earth team as Sentinel's bureaucracy had finally gone too far for him. He was last seen in the third-season finale, "Endgame, Part II", looking on at Optimus, Sari, the Autobots, Omega Supreme, the captured Megatron, Shockwave, and Lugnut, and Blitzwing with a jealous expression on his face.

Transformers Cinematic Universe

In the Transformers film series, Sentinel Prime is a legendary warrior thought to have been lost long ago and is Optimus Prime's direct predecessor and mentor. Unlike his animated counterparts, he plays more as a villain in the real-live version. It was he who taught Optimus the ideals of freedom to all sentient beings. Sentinel is armed with a cosmic rust cannon, a shield and a double-bladed Primax Blade that can be folded into one.

His intention is to restore Cybertron to its former glory. But as the war dragged on, he was driven mad by desperation, with Quintessa corrupting and ordering him to bring Cybertron to Earth (Unicron) on her behalf hoping to destroy it, causing Sentinel to turn against his ideals and ally with Megatron and the Decepticons and eventually become as corrupt and vile as they were. Sentinel Prime is voiced by Leonard Nimoy, who previously voiced the character Galvatron in The Transformers: The Movie back in Generation 1. This was Leonard Nimoy's last major film role in the Transformers robot superhero franchise until his death in 2015.

Movie plot

In the second film of the series, Transformers: Revenge of the Fallen, Sentinel Prime is briefly mentioned in the rambling speech given by Sam Witwicky while under an AllSpark fragment-induced trance, with Sam mentioning a "mission" Sentinel led.

Sentinel Prime appears in the third film, Transformers: Dark of the Moon, later revealed as a rogue Autobot-turned-Decepticon and the main antagonist of the film. Though it was believed that the Space Bridge technology he devised was to turn the tide of the war for the Autobot's benefit, Sentinel Prime made a deal with Megatron in the past to rebuild Cybertron using Earth's resources and enslaving humanity. However, the Ark, Sentinel's ship, was hit during the end of the war on Cybertron trying to leave the planet and eventually crashed on Earth's moon before 1961. Before the impact, Sentinel hid himself in the crash vault with five of his Space Bridge Pillars, including the control Pillar, but he soon ran out of Energon and became incapacitated. His body was recovered many years later by Optimus Prime and Ratchet when the two Autobots come investigating the wrecked ship and was brought to Earth, where he was resurrected with the power of the Matrix of Leadership. Sentinel was distressed that hundreds of his Pillars were missing, and warned Charlotte Mearing that the Decepticons could destroy Earth with the Pillars. He later went out with Optimus to attend a tour of the Earth and admire its sunset, and declined Optimus' offering of the Matrix, due to the fact that he doesn't know much about the Earth.

Sam Witwicky discovers that the Decepticons had taken the missing majority of the Pillars and arranged for the Autobots to find Sentinel and, as they had wanted, revive him, as he was the only one who could use the Pillars to open the Space Bridge. Once the Autobots get him back to their base after a chase with Decepticon Dreads Crowbar, Crankcase, and Hatchet, Sentinel confirms Sam's revelations, but also reveals his secret pact with Megatron and betrays the Autobots, murdering Ironhide and most of the human soldiers to take the five Pillars from the base. After teleporting hundreds of Decepticons to Washington D.C. with the Pillars, Sentinel has a confrontation with Optimus. Though Optimus tries to reason with him, Sentinel coldly rebuffs him, but spares his life in the belief that he would understand the motive for his dubious actions. He demands the exile of the remaining Autobots, who are apparently destroyed while leaving the planet in their space ship. Sentinel later sidelines Megatron and assumes de facto leadership as Prime of the Decepticons to oversee the final phase of the plan. Turning Chicago into their base of operations, the Decepticons place the remaining Pillars around the world to teleport Cybertron close to Earth.

During the final battle, Sentinel battles the Autobots (who faked their deaths) and the human forces, and proves to be more than a match for them. Sentinel then engages Optimus in a duel. At first, Optimus appears to have the upper hand, but Sentinel eventually overpowers him and severs his right arm. However, before Sentinel can execute his former apprentice, Megatron (who had been goaded into action by Carly Spencer) suddenly fires at Sentinel from behind, severely wounding him. The Pillars are destroyed before Cybertron can be teleported completely, which apparently destroys the wayward planet in the process. Optimus refuses Megatron's deceptive offer of a truce and rips his head off, knowing that he will betray him. Seeing his plans in ruins, the wounded Sentinel pleads with Optimus to understand why he had to betray him, but Optimus refuses and claims that Sentinel didn't betray the Autobots, but rather "himself". Optimus then fusillades Sentinel with Megatron's shotgun, avenging Ironhide's death.

In Transformers: Age of Extinction, he was guilty, alongside the Autobots for reviving him, by Chicago's destruction and his remains are used by KSI to build human-made transformers. A scene in the film features the remains of his head being used alongside Megatron's head and other remaining transformers (including Ratchet, Leadfoot, and possibly Sideswipe and Mirage). Also, a photo of Sentinel Prime appears with red X indicating his death in the previous film.

In Transformers: The Last Knight, his ship, The Ark, remains on the moon until the collision between Cybertron and Earth knocks it away.


Sentinel is Optimus's predecessor as leader of Cybertron and Prime. In this universe, where Autobots and Decepticons never went to war, Optimus and Megatron worked together to defeat him after his immoral partnership with the Liege Maximo was exposed.

Kre-O Transformers

Kre-O Sentinel Prime is based on the version of the characters from Transformers: Dark of the Moon.

Transformers: War for Cybertron

Sentinel Zeta Prime was originally an officer in the Elite Guard before being named Prime. Under pressure from the various guilds of Cybertron he oversaw the rise of the caste system that came to dominate Cybertronian society, a policy which brought him into conflict with Alpha Trion, and ultimately led to the archivist's self-imposed exile in the Iacon Hall of Records. By the time of the rise of the Decepticon movement time had robbed him of much of the fire which had made him an effective military leader, and this left him out of touch with the people he claimed to represent.

Animated series

Even though Sentinel Prime is never seen or mentioned in the Transformers: Prime television series, the dead Prime seen in the episode "Alpha/Omega", whose arm was harvested by Megatron so that he could use the Forge of Solus Prime, was identified as Sentinel in The Art of Prime. However, The Covenant of Primus identifies him as the Liege Maximo.