Suspected suicide bomber Kabir Ahmed left Derby to join IS. Simon Cox investigates why.
In the wake of the massacre in Norway, James Silver reports on extremism in the UK.
After terrorist shootings in Europe, how vulnerable is the UK to a similar attack?
Edward Stourton and 4 British Muslim journalists discuss the extremist threat to the UK
Professor Gretchen Gerzina explores the lives of black sailors in the British Navy.
Sangita Myska investigates the secret story of Britons held as slaves.