The Transformers toyline and cartoon series owed their existence to the Japanese toyline, Microman (an Eastern descendant of the 12" G.I. Joe action figure series). In 1980, the Microman spin-off, Diaclone, was released, featuring inch-tall humanoid figures able to sit in the drivers' seats of scale model vehicles, which could transform into humanoid robot bodies the drivers piloted. Later still, in 1983, a Microman sub-line, MicroChange was introduced, featuring "actual size" items that transformed into robots, such as microcassettes, guns and toy cars. Diaclone and MicroChange toys were subsequently discovered on show at the 1983 Tokyo Toy Fair by Hasbro toy company product developer Henry Orenstein, who presented the concept to Hasbro's head of R&D, George Dunsay. Enthusiastic about the product, it was decided to release toys from both Diaclone and MicroChange as one toyline for their markets.

Once the Federal Communications Commission did away with regulations that prohibited toy companies from broadcasting cartoons based on their products in 1984, the way was cleared for the new product-based television program.

Hasbro had previously worked with Marvel Comics to develop G.I. Joe: A Real American Hero for a three-pronged marketing scheme - the toyline, a tie-in comic book by Marvel, and an animated mini-series co-produced by Marvel's media arm, Marvel Productions, and the Griffin-Bacal Advertising Agency's Sunbow Productions animation studio. Given the success of that strategy, the process was repeated in 1984 when Hasbro marketing vice president Bob Prupis approached Marvel to develop their new robot series, which Jay Bacal dubbed "Transformers."

Marvel’s Editor-in-Chief at the time, Jim Shooter, produced a rough story concept for the series, creating the idea of the two warring factions of alien robots – the heroic Autobots and the evil Decepticons. To flesh out his concept, Shooter called upon veteran editor Dennis O'Neil to create character names and profiles for the cast, but O’Neill’s work – for whatever reason – did not meet with Hasbro’s expectations, and they requested heavy revisions. O’Neill declined to make said revisions, and the project was turned down by several writers and editors approached by Shooter until editor Bob Budiansky accepted the task. Hastily performing the revisions over a weekend, Budiansky’s new names and profiles were a hit with Hasbro, and production began on a bi-monthly four-issue comic book miniseries, and three-part television pilot.

Japanese designer Shōhei Kohara was responsible for creating the earliest character models for the Transformers cast, greatly humanising the toy designs to create more approachable robot characters for the comic and cartoon. His designs were subsequently simplified by Floro Dery, who went on to become the lead designer for the series, creating many more concepts and designs in the future.

Plot

For the purposes of plot, The Transformers: The Movie (1986) is considered part of the series. This plotline reflects only the events depicted in this cartoon series, and in the accompanying movie.

Skywarp and Thundercracker flying above Cybertron, before their arrival on Earth.

Four million years ago, on a distant planet called Cybertron, life existed in the form of sentient robots which could think and feel, called Transformers. The race of Transformers was divided into two main clans. Autobots (known as Cybertrons in the Japanese cartoon), led by Optimus Prime, wished for peaceful co-existence. Decepticons (known as Destrons in the Japanese version), under the command of Megatron, sought conflict and universal conquest. Both sides were embroiled in an ages old war for supremacy.

With both sides running low on energy, the Autobots, aboard the Ark, sought out a new source, but the Decepticons, aboard their space-cruiser (later given the name Nemesis in the Beast Wars animated series), ambushed them in hopes of gaining a decisive advantage. The Decepticons boarded the Ark and the ensuing space battle resulted in both the ships crash landing on a pre-historic Earth, the Ark crashing into the side of a dormant volcano. (The fate of the Nemesis is subject to retroactive continuity. For the full story, see the Nemesis article.)

Four million years passed while the Autobots and Decepticons lay dormant aboard the Ark. In the Earth year 1984, the volcano housing the Ark erupted, reawakening the ship's computer, Teletraan I, which then modified the Transformers so as to give them alternate modes that could blend in on Earth.

The Autobots and Decepticons, now stuck on Earth, continued their war more ferociously than ever. The Decepticons wished to drain Earth of all its resources, converting it into energon for their use, while the Autobots were committed to stopping them, and to protecting the human race. This era would later be referred to by Transformers as the "Great War." The war was almost ended as soon as it began, as the Decepticons gained an early lead, and were even able to build a space cruiser to leave Earth, however Autobot intervention prevented them from escaping orbit.

Devastator and Snarl face off.

New allies were gained on both sides. Humans Sparkplug Witwicky, and his son Spike Witwicky, allied with the Autobots, while the human Doctor Arkeville sided with the Decepticons. Jetfire and the Insecticons were discovered already living on Earth. Both sides even built new allies to join their cause, the Autobots building the Dinobots and the Aerialbots, and the Decepticons building the Stunticons and the Combaticons. They were later joined by some allies who had been elsewhere in the universe including Omega Supreme and the Constructicons.

Despite wild gimmicks on both sides, including attempts to build better weapons, to undermine history through time travel, and even a temporarily successful attempt to warp Cybertron into Earth's orbit, neither side gained an overwhelming advantage, despite the Decepticons being defeated by the Autobots in nearly every episode. In the long run however, the Decepticons took the lead in the Great War, creating a Space Bridge that allowed them to warp individual Transformers to and from Cybertron at any time. This allowed them to claim rule of Cybertron, which gave them the winning edge for many years.

All of this changed in 2005, over 20 years after the start of the Great War. The Decepticons launched a surprise attack on Autobot City, on Earth. Countless Transformers lost their lives in the battle for Autobot City, but the Decepticons were repelled thanks to Optimus Prime's victory over Megatron, a victory that came at the cost of his own life.

Megatron and the other wounded Decepticons were abandoned by the stronger members of the team, in part due to Starscream's desire to usurp Megatron as leader. The God-like Unicron found them drifting in space. He rebuilt Megatron as Galvatron, and sent him on a quest to destroy the Autobot Matrix of Leadership. The Autobots' new leader, Rodimus Prime, was able to stop the Decepticons however. In his first battle as leader, he destroyed Unicron, reclaimed Cybertron for the Autobots, and expelled Galvatron into deep space.

The Decepticons, without focus and dangerously low on energon, retreated to the burnt out world Charr. It was there they waited, until Cyclonus discovered Galvatron was simply expelled and not killed. Upon rescuing Galvatron, the Decepticons renewed their efforts to vanquish the Autobots and to claim complete control of Cybertron.

Both the Autobots and Decepticons soon learned they had a common enemy. A secretive race known as the Quintessons plotted the destruction of both Autobots and Decepticons. Rodimus Prime learned that these "new" Quintessons were no strangers to the Transformers at all. Rather, the Quintessons were the original creators of the early Transformers. Cybertron was a Quintesson factory before it was ever the Transformers' "home." The Quintessons went so far as to destroy their own home world in an attempt to vanquish the Transformers. In the end, the Quintessons, who relied on thorough probability analyses, were outdone by a now adult Spike Witwicky whose actions, unlike those of the robotic Transformers, the Quintessons were not able to predict.

The Great War continued, this time with the Autobots controlling Cybertron, and enjoying the advantage. The war was no longer waged primarily on Earth. Now, the whole universe was their battlefield.

In 2006, a disease called the Hate Plague was released upon the universe. This disease, which infected human and Transformer alike, threatened to destroy everything. With their leader Rodimus Prime infected, the remaining Autobot Sky Lynx and a Quintesson finished rebuilding Optimus Prime, who was able to reclaim the Autobot Matrix of Leadership from Rodimus Prime and use it to eradicate the Hate Plague, draining the Matrix of all the power it had possessed.

Optimus Prime retains leadership of the Autobots. While the Decepticons continue to pose a threat to peace, Optimus Prime vows to resist Decepticon rule forever.

[edit] Other Transformers continuities

The comics produced by Marvel between 1984 and 1991 tell a substantially different version of the story. Both versions were equally authorized by Hasbro.

http://en.wikipedia.org/wiki/The_Transformers_(TV_series)#Production_background