The second place in this year's final is at stake, as a further four first-round winners compete in this semi-final, which takes place in the Nereid Room at the British Museum in London.
Gerard Godfrey (accountant) The life and reign of Henry VIII
Michael Macdonald-Cooper (freelance writer)
The poems of Rudyard Kipling
John Bowers (chartered town planner) The history of the Isle of Man Michael Formby (chartered surveyor) History and architecture of Lincoln Cathedral from 1072