Dan talks to Mike Martin about the reasons humans fight, why they are willing to die for their countries, and how ideology can lead someone to blow themselves up.
Dr Marc Morris is an historian and broadcaster, specialising in the Middle Ages. He is the author of 'William I: England's Conqueror'.
The Williamson Tunnels are a labyrinth of tunnels in the Edge Hill area of Liverpool, England, which were built under the direction of the eccentric businessman Joseph Williamson between 1810 and 1840.
David Lammy, whose urgent question to Amber Rudd in the House of Commons provoked an international response, talks to Dan about how British history is colonial history, and what histories currently aren't told in our national story.