Six years ago, a man largely unknown in the west was given one of the most important jobs in the world. China's new president, Xi Jinping, became the leader of a rising superpower, commander of a formidable military, and the head of an economy that's crucial to people's lives around the world. This programme tells the extraordinary story of his controversial six-year rule, and how he set about transforming China into a tightly controlled state where loyalty to the Communist Party appears to be valued above everything else.