Genghis Khan was one of the most feared and most famous warrior kings in history. But how did he rise to power to become the Emperor of the Mongol Empire? How did he unite many of the nomadic tributes of North-East Asia, and then conquer most of Eurasia? Why is he considered a hero in modern-day post-Communist Mongolia? Rob Weinberg asks the big questions about this notorious figure to military historian Major Gordon Corrigan