It was at his elite boarding school in West Africa that Kofi Annan – the man who would later become the world’s top diplomat – learnt one of his most important lessons. It was, he said later, “that suffering anywhere concerns people everywhere”. The idea seems to have inspired Annan throughout a life which saw him play a key role in the crises which have shaped the world, from the HIV/Aids pandemic, to the Iraq War and, latterly, climate change. His humanitarian work would win him a Nobel Peace Prize, but it would also win him a raft of critics. Annan, the first black African to lead the United Nations, would nonetheless became one of the most enduring and recognised diplomats in modern history.