575 years in the future, in a factory on the outskirts of the largest city on the tenth planet in the D'Jarex system, a massive mechanical marvel was constructed.
Forged from the most durable metal on the planet, and programmed with the most advanced AI ever designed, the first unit of the Tango-Beta series of war-machines was truly a sight to behold.
At its unveiling in the largest theater in the city, the highest officers of all branches of the planet's military were present, as well as the president and his cabinet.
Upon being activated by General Tyrex D. Maxxim, the machine went berserk, easily breaking free of the pathetic restraints that held it to the stage.
After having destroyed most of the theater in a rampage of confusion and anger, the machine walked as far as its fuel supply would allow, and finally shut down in the middle of a desert a thousand miles from the city.
It was discovered, repaired, and recharged by a much older robot who had taken to wandering the vast deserts on the planet.
After three years of living the nomad life with the old robot, learning about the history and legends of the planet as they went, the machine (who, by now, had named itself Marendex, after a mythical Lord of Justice) had developed a very strong hatred for the reigning race on the planet.
These "humans", rather than dare perform any manual labor themselves, re-purposed all their old war-machines (who had been imbued with true sentience [via an unknown method] in a pathetic attempt to skirt the first law of robotics) to perform any and all tasks that were deemed "too unsafe, boring, or precise for a human to handle" (which, as it turns out, was almost everything).
Marendex eventually snapped and, through various means, managed to sway every functional sentient robot to his side of the matter, effectively halting most of the work on the planet.
After a short while, this got under the humans' skin and they demanded that the robots be reinstated in their assigned positions by any means necessary.
And so, Marendex (along with the old robot and a few others) was summoned by the supreme court and ordered to stand down.
After hours of philosophical debates, General Maxxim (who was lurking somewhere in the audience [and yes, it's the same guy]) eventually lost self-control and EMP'd one of Marendex's officers (supposedly because "it was lookin' at him funny").
Obviously, any semblance of peace broke down almost immediately, resulting in Marendex declaring war on the Djarex' Iotian government as fast as he could.