For 50 years Guardian readers have been stumped by the fiendishly difficult General Knowledge Paper set annually at Christmas for the pupils of King William's College, on the Isle of Man. Here, for the first time, is a compendium of the GKP questions and answers from 1981 to 2010 with aspecial bespoke set of questions compiled for the book by quizmaster Dr Pat Cullen. Guaranteed to challenge even the most ardent enthusiast, this book can genuinely claim to contain the world's most difficult quiz. **Answers to bespoke set of questions published 1st July, 2012. Please emaillup@liv.ac.uk to request a copy.**