The Companion on Humanitarian Action addresses the political, ethical, legal and practical issues which influence reactions to humanitarian crisis. It does so by exploring the daily dilemmas faced by a range of actors, including policy makers, aid workers, the private sector and the beneficiaries of aid and by challenging common perceptions regarding humanitarian crisis and the policies put in place to address these. Through such explorations, it provides practitioners and scholars with the knowledge needed to both understand and improve upon current forms of humanitarian action. The Companion will be of use to those interested a range of humanitarian programmes ranging from emergency medical assistance, military interventions, managing refugee flows and the implementation of international humanitarian law. As opposed to addressing specific programmes, it will explore five themes seen as relevant to understanding and engaging in all modes of humanitarian action. The first section explores varying interpretations of humanitarianism, including critical historical and political-economic explanations as well as more practice based explorations focused on notions needs assessments and evaluation. Following this, readers will be exposed to the latest debates on a range of humanitarian principles including neutrality and sovereignty, before exploring the key issues faced by the main actors involved in humanitarian crisis (from international NGOs to local community based organizations). The final two sections address what are seen as key dilemmas in regards to humanitarian action and emerging trends in the humanitarian system, including the increasing role of social media in responding to crises. Whilst not a ‘how to guide’, the Companion contains many practical insights for policy makers and aid workers, whilst also offering analytical insights for students of hu