Susan Williams has published widely on Africa, decolonisation and the global power shifts of the twentieth century. Her widely acclaimed book on the founding president of Botswana, Colour Bar (Penguin, 2006), recently became a major motion picture (A United Kingdom). Who Killed Hammarskjöld? (2011) triggered a fresh UN inquiry into the death of the secretary general. She is a Senior Research Fellow at the Institute of Commonwealth Studies, University of London.