As the United Nations Decade of Education for Sustainable Development (DESD) approached its midpoint, the “UNESCO World Conference on Education for Sustainable Development – Moving into the Second Half of the UN Decade” was held from 31 March to 2 April 2009 in Bonn, Germany. It brought together 900 participants from 147 countries, among them 49 Ministers and Deputy-Ministers. Participants included representatives of UNESCO Member States, UN agencies, civil society organizations, education institutions, youth, and the private sector, as well as individual experts. The Conference was organized by UNESCO and the German Federal Ministry of Education and Research, in cooperation with the German Commission for UNESCO. The programme was developed in consultation with an international advisory group.