Bigon

Bigon was originally a Greek philosopher. He and other Greeks were abducted by Monarch on his fourth visit to Earth and converted into androids.

Bigon was promised he would rule over Europe once the planet had been conquered, but he rejected this offer, as he believed democracy was the best form of government. Monarch kept him to provide an element of doubt in his perfect society; he believed it was an intellectual galvaniser.

Bigon helped the Fifth Doctor defeat Monarch. The androids decided to look for another planet to settle on. (TV: Four to Doomsday)