In 1258, as baronial opposition to Henry III erupted and the government became locked in constitutional conflict, the country found itself in the grip of a serious food crisis. To blame was a run of bad weather and failed harvests. Thousands of famished famine refugees flocked to London in quest of food and charity, where many of them perished and were buried in mass graves. The multiple burials recently discovered and excavated in the cemetery of the hospital of St Mary Spital highlight the plight of the poor at this time of political turmoil. Was their fate part of a global catastrophe precipitated by the VEI7 explosion of Samalas Volcano, Indonesia, the previous year or was powerful solar forcing of global climates responsible for the unusually unstable weather? The answer depends in large measure upon establishing the precise chronology of how the crisis unfolded, drawing upon the surviving documentary record of prices and harvests, the comments of contemporary chroniclers and a range of high-resolution palaeo-climatic proxies. Reexamination of this episode illustrates the potential of environmental history to shed fresh light on familiar historical events and its capacity to place them in a global environmental context.