This paper examines the origins and evolution of the concept of policy coherence and its implications in practice. It is particularly concerned to understand the precise character of the new relationship proposed between aid and foreign policy in the post-Cold War era. This paper summarises the findings of an HPG study that analysed the evolution of the concept of coherence in the last decade and its implications for the relationship between humanitarian and political action. The study focussed on the global policy responses of two donor governments – the UK and the Netherlands – and of the United Nations, to complex political emergencies. In addition, it looked at particular examples of approaches to coherent humanitarian programming in Afghanistan, Macedonia and Serbia.