When it comes to deciding the most tragic British artist of the 20th century, Cyril Mann (1911-80) must be a contender. Mann made a number of genuinely innovative breakthroughs and certainly had the potential to become one of the most important figurative painters of his time. Yet, struggling with mental health problems, Mann had an unerring instinct for turning each moment of promise into bitter disappointment. In 1959, Renske...