By the time Abba split up, no one was in any doubt that behind the glitter there was a dark side, and behind the smiling group were four troubled individuals. But even as a whole new generation of fans discovers Abba’s great music, Anni-Frid, Agnetha, Benny, and Bjorn have continued to remain rather shadowy, secretive figures. Their marriages, personal break-ups and superficial biographical details are well known…but who exactly were Abba?