Alan Turing. As Larry Kramer says in The Normal Heart:
"Did you know that it was an openly gay Englishman who was as responsible as any man for winning the Second World War? His name was Alan Turing and he cracked the German’s Enigma code so the Allies knew in advance what the Nazi’s were going to do - and when the war was over he committed suicide he was so hounded for being gay. Why don’t they teach any of this in schools?"