Who is China's President Xi Jinping?

China's President Xi Jinping has arrived in the UK at the start of a four-day state visit. The British government is keen to develop its relationship with China, with Prime Minister David Cameron hailing a "golden era" in ties between the two nations. But the visit is being tightly controlled, with no television interviews or news conferences planned. China Editor Carrie Gracie charts Mr Xi's rise from banished farmer to the country's most powerful leader since Chairman Mao - from BBC News