The institutions included in this book - four United Nations bodies, the Food and Agricultural Organization (FAO), the International Fund for Agricultural Development (IFAD), the World Bank, and the World Food Programme (WFP), and the Consultative Group on International Agricultural Research (CGIAR) - play important roles in achieving and maintaining world food security that is essential for human existence, economic and social development and world peace. The origins, functioning and work of these institutions, their successes and difficulties, and their continuing relevance to meet the challenges of the Twenty-First century are comprehensively examined.