Professor Yeo was Principal of Ruskin College, Oxford, 1989-97 and since then has been Chair of the Co-operative College and the Co-operative Heritage Trust in Manchester and Rochdale, engaging with and writing about the movement. Stephen began his adult life as a Labour Party Parliamentary candidate in the elections of 1964 and 1966. As a social historian, he is known for his work on association, cooperation, labour movements and religious and voluntary organisations. He taught at the University of Sussex for 25 years, and he was also active in Brighton's community politics.