Mosley, Sir Oswald (Ernald), 6th Baronet (1896-1980), English Fascist leader. Successively a Conservative, Independent, and Labour MP, he founded the British Union of Fascists, also known as the Blackshirts, in 1932. The party was effectively destroyed by the Public Order Act of 1936. In 1948 Mosley founded the right-wing Union Movement.