Markotics

It is revealed that thousands of years before Optimus Prime and the other Transformers arrived on Earth, there was a race of ancient Transformers who scoured the universe looking for Energon sources. Known as the Dynasty of Primes, they used a weapon called the Sun Harvester to drain stars of their energy in order to convert it to Energon and power Cybertron's AllSpark. The Primes agreed that life-bearing worlds would be spared, but one brother, who was thereafter dubbed "The Fallen", constructed a Sun Harvester on Earth in 17,000 BCE. The remaining brothers thus sacrificed their bodies in order to hide the Matrix of Leadership—the key that activates the Sun Harvester—from The Fallen, who swore to seek revenge upon Earth once he found the key. (Excerpt from Wikipedia)

The movie rocks! I can only say that much. My keyboard is not functioning well so I just copied an excerpt on the web. The movie is divided into 2 links and the quality is good (please be informed that this is not a DVD copy, just a cam version) but it's good.

So, click here if you want to watch Part 1. And here's Part 2 once you get done.