The British Red Cross (BRC) has played a pivotal role in the history of war, international relations, humanitarianism and health in modern Britain, and interest in the charity has been piqued by the centenary of the First World War. Exhibitions, television series and the film Testament of Youth (2014) have highlighted the work of Red Cross volunteers. The History of the British Red Cross, 1870-2020 tells the broader story of the BRC within politics and society. Major episodes in modern British political and military history are integral to the story of the BRC, from the second wave of European colonialism and the South African War, to the two World Wars. Following the Second World War, the BRC provided vital support for the new National Health Service, organised civil defence activities during the Cold War, and responded to the suffering resulting from the actions of terrorists from the IRA to Al-Qaida. As Britain's representative to the International Committee of the Red Cross (ICRC), and the International Federation of Red Cross and Red Crescent Societies, the charity plays a key role in international relations and disaster relief. The 150th anniversary of the establishment of the National Society for Aid to the Sick and Wounded in War, founded in 1870 as the United Kingdom's member of the ICRC, provides a ripe opportunity for the publication of the first fully-contextualised account of the history of the BRC.