A long-serving Guardian, the earliest recorded history of Leader-1 comes from the first Renegade revolt. His help stopping the Renegades, and battling Parthian Raiders, was recognised when he was appointed a High Protector of Gobotron, along with his good friend Cy-Kill and the respected statesman Zeemon. He rejected the ambitious Cy-Kill's offer to help him take over Gobotron, and then an offer from the Guardian Council to make him overall leader of Gobotron, strongly believing that no Gobot should be master of another. He was greatly hurt when his comrade instead defected to the Renegades to achieve his goal by conquest, and only narrowly escaped an assassination attempt devised by Cy-Kill. The latter's defection and the lasting damage caused to Zeemon on Parthis left him as de facto field commander of the Guardians.
Cy-Kill soon rose to command of the Renegades, and was a constant thorn in the Guardians' side. Leader-1, along with his loyal comrades Turbo and Scooter, would make his first visit to Earth in 1984 while chasing Cy-Kill. With his fellow Guardians and a few human allies, the Guardians were eventually able to thwart Cy-Kill's plans to use Earth as the launching point for a vast force of Zods. Leader-1 was captured during the battle, but managed to use his initiative to disable a Zod before he could be destroyed.
He formed a friendship with the human astronauts Matt, AJ and Nick, and would frequently team up with Matt to combat the Renegades. The Guardians formed an alliance with the human military organisation UNECOM, and Leader-1 would divide his time between his responsibilities on Gobotron, defending Earth (now a regular target of Cy-Kill) and patrolling other areas of space.
After the return of the Master Renegade, Cy-Kill mounted an all-out attack on Gobotron. Leader-1 was shot down defending the planet, and then disassembled. However, his components were recovered, and he was rebuilt by the Last Engineer. Leader-1 was then instrumental in testing the Last Engineer's Powersuit system, and led the Guardian counterattack, driving off the Renegades and retaking Gobotron.
His escapades on Earth are too numerous to list, but they include regularly thwarting Cy-Kill's various plans, deflecting an invasion attempt by the Insectoids of Level 21, helping destroy the rogue UNECOM robot Sentinel and preventing the return of the ancient Gobot known as the Evil One, not to mention defeating Renegade projects such as Ultra Zod and the Puzzler. On Gobotron he was instrumental in freeing Earth's hostage population and thus overcoming Cy-Kill's attempt to seize control of the planet, convinced the alien Al-Vanar not to invade the planet and helped overthrow Gunnyr's underground dictatorship. Further afield, he led a Guardian assault on Cy-Kill's flagship Roguestar, saved the population of the planet Tri-Ceti from the Renegades, freed captives from the Gameworld of Kolob and helped destroy a Renegade mining facility in the Vega System.
However, it wasn't all plain sailing for Leader-1. His old friendship from Cy-Kill (and his firm belief the Renegades should be captured and tried, rather than killed) meant he could never quite bring himself to finish off his enemy. It also exposed his optimism at times, such as when Cy-Kill arranged peace talks in Vienna. On that occasion Leader-1 was too trusting of the Renegades and only Turbo's actions saved Earth. He twice came under heavy censure from the Guardian Council once after relying on an untested scanner system devised by Scooter left Gobotron interests inadequately protected, and once when Man-O-War believed he was not doing a good enough job defending the planet. However, he came through these crises with his reputation largely intact. More of a problem were the number of times he was captured, shot down, copied or controlled, usually being bailed out by his team-mates. Leader-1's greatest strength, perhaps, was his ability to inspire loyalty in his fellow Guardians and assemble teams of specialists best equipped for responding to the threats they faced.
In addition to being able to transform into a jet (which allows him greater speed, including access to his afterburners, and mobility than simply flying in his robot mode), Leader-1 is equipped with a strong, but power-thirsty, forcefield. He is capable of carrying a pilot in jet mode (usually UNECOM's Matt Hunter), and of storing someone safely in his chest compartment in robot form.
Leader-1 appeared in the following episodes:
"The Battle for Gobotron", "Target Earth", "Conquest of Earth", "Earthbound", "The Final Conflict", "Cy-Kill's Escape", "Quest for the Creator", "The Fall of Gobotron", "Flight to Earth", "Return to Gobotron", "Time Wars", "Renegade Alliance", "Genius and Son", "Dawn World", "Forced Alliance", "Invasion from the 21st Level Part I", "Invasion from the 21st Level Part II", "Lost on Gobotron", "Cy-Kill's Shrinking Ray", "Quest for Roguestar", "Renegade Rampage Part I", "Renegade Rampage Part II", "Ultra Zod", "Sentinel", "Cold Spell", "Auto-Madic", "Tarnished Image", "In Search of Ancient Gobonauts", "Gameworld", "Wolf in the Fold", "Depth Charge", "Nova Beam", "Transfer Point", "Steamer's Defection", "The Gobot Who Cried Renegade", "The Seer", "Whiz Kid", "Pacific Overtures", "Destroy All Guardians", "Escape from Elba", "Clutch of Doom", "The Third Column", "A New Suit for Leader-1", "Renegade Carnival", "The Gift", "The Last Magic Man", "Braxis Goes Bonkers", "Inside Job", "Fitor to the Finish", "Cy-Kill's Cataclysmic Trap", "Doppelganger", "Trident's Triple Threat", "Speed is of the Essence", "Crime Wave", "Scooter Enhanced", "Ring of Fire", "Element of Danger", "It's the Thought That Counts", "The Gobots That Time Forgot", "Guardian Academy", "Quest for New Earth", "The Secret of Halley's Comet", "Terror in Atlantis", "Et Tu, Cy-Kill", "Mission Gobotron", Gobots: Battle of the Rock Lords