The perception that humanitarian response does not always meet the basic requirements of affected populations in a timely fashion and that the response provided can vary considerably from crisis to crisis prompted the Emergency Relief Coordinator (ERC) to launch an independent Humanitarian Response Review (HRR) of the global humanitarian system. This review was conducted by four independent consultants adopting a bottom up approach, and the report is based on the results of the analysis of material collected through customized questionnaires, interviews, seminars, background documents, as well as the results of a number of evaluations and lessons learned exercises. The review covered complex emergencies and natural disasters. The team gave special attention to reviewing the preparedness of the international humanitarian organizations to predict crises, prevent them, mitigate their impact on vulnerable populations and respond effectively to their needs.