In 1953 Dag Hammarskjöld became the second Secretary-General of the United Nations—the highest international civil servant. Before his mission was cut short by a 1961 plane crash in then Northern Rhodesia (today Zambia), he used his office to act on the basis of anti-hegemonic values, including solidarity and recognition of otherness. The dubious circumstances of Hammarskjöld’s death have received much attention, including a new official investigation (which is summarized in a chapter), but have perhaps overshadowed his diplomatic legacy—one that has often been hotly contested. This book summarizes Hammarskjöld’s personal background and the normative frameworks of the United Nations. He then explores the years of African decolonization during which Hammarskjöld was in office, investigating the scope and limits of his influence within the context of global governance during the Cold War. It paints a picture of a man with strong guiding principles, but limited room for maneuver, colliding with the essential interests of the big powers as the ‘wind of change’ blew over the African continent. The book is a critical contribution to the study of international politics and the role of the UN in the African decolonization processes during the Cold War. It is also exploring the role of individuals in leadership positions of the international civil service and by doing so is a tribute to the achievements of a cosmopolitan Swede.