A new series of the celebrity version of Britain's toughest quiz. Tonight's contenders are Paul Bradley, Dan Snow, Peter Serafinowicz and William G Stewart. Show more

Four more celebrities face John Humphrys and the black chair. The contenders hoping to show off their knowledge are Ade Edmondson, Bill Turnbull, Jan Ravens and Benjamin Zephaniah. Show more

John Humphrys questions the famous contenders in a Celebrity version of Britain's toughest quiz. Tonight's contenders are Steve Cram, Anjum Anand, Tony Hawks and Bill Kenwright. Show more

John Humphrys asks the questions in this Celebrity version of television's toughest quiz. Being quizzed on their specialist subjects are Wayne Sleep and Yvette Fielding. Show more

Kaye Adams, Simon Rimmer, Danny Wallace and Nicholas Parsons sit in the dreaded black chair as John Humphrys asks the questions.