In the first of a two-part series, Dr Jago Cooper reassesses the achievements of the Inca Empire. He begins in Peru, where evidence is still being uncovered that challenges preconceptions about its origins and significance. Venturing from the coast to the clouds, he reveals how the Inca transformed one of the most challenging landscapes in the world to ward off the worst effects of the climate, and created sophisticated systems of communication. He shows how one of many independent societies became a commanding empire - not through force, but by using subtle methods of persuasion.