This helpdesk reports that defining famine has proved historically challenging. The Integrated Food Security Phase Classification (IPC) provides a common currency for classifying both the magnitude and severity of food insecurity through a set of standardised tools. Despite the standard definition that the IPC provides, there have been several incidents where mass nutrition related mortality have been recorded, that are not classified as famine. This helpdesk provides a synthesis of the evidence available on the major famines and similar crises since 1980. It provides data, where available, on Global Acute Malnutrition (GAM) and Severe Acute Malnutrition (SAM). It includes a discussion on why better data is needed to address famine and why evidence is needed to overcome food insecurity. The helpdesk identifies the main causes of mortality during famines as reported in the literature. To complement the synthesis of the evidence, an annotated bibliography is included. This provides an abstract and link for each resource used, making it easy for the reader to access the evidence directly.