Dr. Harold Winston was a scientist and part of the mission crew of the Horizon Lunar Colony. He was one of the caretakers of the genetically enhanced gorillas housed there, including one that exhibited extreme intellect.
Harold and his fellow scientists were killed in the primate uprising that wrested control of the base from the humans. The single gorilla that had bonded so closely with him, however, did not participate, and instead escaped to Earth, taking the name of his beloved caretaker as his own. He joined Overwatch, known by the name Winston.