A wholly comprehensive, clearly presented and accessible text covering the totality of the peacekeeping experience since the early/mid-20th century. Essential reading for undergraduates on Politics, International Relations and Contemporary History programmes, it will also be a significant resource for taught postgraduate courses in these subject areas. The narrative is primarily chronological but key themes such as legality and 'collective security' are traced throughout. The chronology itself is based on key periods in the development of peacekeeping marking stages in the evolution of the concept determined by changes in the nature of the international system over the past six decades.