The reason for the decline of Orson Welles's career is a hotly debated issue, but decline it certainly did.When Citizen Kane, his first film, opened in 1941, Welles was universally acclaimed as the most audacious filmmaker alive.But instead of marking the beginning of a triumphant career in Hollywood, the film still regularly voted the greatest ever made proved to be an exception in Welles's life and work.In 1947 Welles left America for Europe and lived for the best part of twenty years in self-imposed exile.Welles himself famously quipped 'I started at the top and worked my way down' - the second volume of Simon Callow's compelling biography tells the story of that complex and protracted descent from grace.