In 1985, rock band U2 and manager Paul McGuinness commissioned him to write the story of their origins, formation, early years and the time leading up to their highly successful album "The Joshua Tree". His book "Unforgettable Fire - Past, Present, and Future - The Definitive Biography of U2" was published in 1988. It received some favourable reviews, but critics close to the band spoke of many inaccuracies. A verbal war erupted in the press during which Dunphy called lead singer Bono a "pompous git".