Even today, there are pubs and a horse race named after John of Gaunt, a 14th century prince and warrior who rose to become one of the most powerful men in England, and whose son would return from exile to claim the throne, and found the House of Lancaster. Author and historian Guy Walters talks to Helen Carr, author of The Red Prince, on how John of Gaunt schemed his way through a real-world game of thrones, becoming the forefather of all English kings and queens.