Bolivar Trask

Bolivar Trask is the creator of the Sentinels and by default an enemy of mutant-kind, putting him into conflict with the X-Men and Charles Xavier - however unlike his creations Trask was not an inherently evil man and ultimately sacrificed himself to stop his mad creations.

History
When his own son developed mutant powers, Trask set out to learn everything he could about mutation. He hired a team of scientists to develop a device that would inhibit his son's powers. He finally came to the conclusion that mutants would inevitably use their superhuman abilities to supplant Homo sapiens. Another team of scientists developed and built the Sentinels in a secret laboratory. Trask wrote several articles on the "mutant question," but when he made an appearance on television, Professor Xavier realized that such propaganda must be rebutted. During the resulting debate, Trask demonstrated his robots, which unexpectedly left for their lab and took Trask with them.

Back at the lab, Master Mold, the prototype Sentinel, confronted Trask. It had come to the conclusion that Sentinels were superior to both races: thus, robots could and should supplant humans and mutants. Taking orders from a mere human ran counter to this new imperative, so Trask would thenceforth serve the Sentinels and help build more of them.

Meanwhile, the Sentinels had also taken prisoner an X-Man, the Beast. Master Mold ordered Trask to use a psycho-probe to read the Beast's mind and learn their plans. Trask learned, however, that the X-Men were protecting humanity and that his theory was wrong. This revelation, coupled with Master Mold's betrayal and the threat to humanity, told Trask what he must do: destroy the laboratory and the Sentinels. He died in the resulting explosion.

Unfortunately, Trask's propaganda, as well as several new and improved Sentinels, persists to this day.

The Purifiers, under the orders of Bastion, and using Technarch technology later resurrected Trask.