Andrei Sakharov

Few people had more reason to stay loyal: Sakharov was a principal designer of the Soviet hydrogen bomb, three times a Hero of Socialist Labour and a full member of the Academy of Sciences. In 1968 he circulated an essay arguing that intellectual freedom was essential to humanity's survival, lost his weapons work, and spent the next two decades defending dissidents, standing outside their trials and going on hunger strike. He was exiled to Gorky in 1980 after condemning the invasion of Afghanistan. Freed by Gorbachev in 1986, he went on to criticise Gorbachev too, from the floor of the new Congress of People's Deputies.