Professor Whitaker was a British scientist who developed a working time travel theory. He applied for a government grant, but was turned down, and after being ridiculed for his ideas, dropped out of the public eye and began secretive work on a machine that could manipulate time.
He later worked with Sir Charles Grover on Operation Golden Age, but their plans were exposed by the Third Doctor. When Grover activated Whitaker's time machine, it sent them to an unknown point in the past. (TV: Invasion of the Dinosaurs)