The Transformers: The Movie

The Transformers The Movie is a 1986 American animated feature film based on the animated TV series by the same name. It was released in North America on August 8, 1986 and in the UK on December 5, 1986.

In 2005, the war between the Autobots and Decepticons has culminated in the Decepticons conquering their homeplanet Cybertron, while the Autobots operate from its moons preparing a counteroffensive. Optimus Prime sends an Autobot shuttle to Earths Autobot City for Energon supplies, but the Decepticons led by Megatron, commandeer the ship, killing the crew. Travelling to Earth, the Decepticons attack Autobot City, slaughtering many Autobots and leaving only a small group alive including Hot Rod, Kup, Ultra Magnus, Arcee, Springer, Blurr, Perceptor, Blaster, and the human Daniel Witwicky. The next day, Optimus and the Dinobots arrive as reinforcements. Optimus singlehandedly defeats the Decepticons and engages Megatron in a climatic battle that leaves both of them mortally wounded. On his death bed, Optimus passes the Matrix of Leadership to Ultra Magnus, informing him that its power will light the Autobots darkest hour, before he dies.Elsewhere, the Decepticons jettison their wounded from Astrotrain, including Megatron at the hands of his treacherous air commander Starscream. The wounded are found by Unicron, a gigantic sentient cyberplanet who consumes other planets, and offers Megatron a new body in exchange for destroying the Matrix which has the ability to destroy him. Megatron agrees and is converted into Galvatron, gaining new troops from the other Decepticons present. Going to Cybertron, Galvatron crashes Starscreams coronation as Decepticon commander and destroys him, before travelling to Autobot City to eliminate Ultra Magnus. The surviving Autobots escape in separate shuttles, but both are damaged by the Decepticons and crash land on different planets. ........

Source: Wikipedia