When a failed military coup provoked civil war in Spain in July 1936, the tremendous numbers of casualties obliged the Spanish government to make a worldwide plea for medical assistance. Many thousands of people around the world rallied to the call, transforming the Republican Medical Service into a truly international effort. Some of those volunteers worked in emergency blood transfusion facilities, carrying out pioneering transfusion work in primitive and often dangerous conditions. Among the most notable of these volunteers were Canadian surgeon Norman Bethune and British doctor Reginald Saxton. Working alongside them were American, Italian and Spanish assistants, many of whom remain nameless. All played vital roles in the saving of lives and all took their lead from one man—the young Catalan haematologist, Frederic Duran Jordà, director of the Blood Transfusion Service of the Republican Army, and indisputable pioneer of Civil War blood transfusion medicine.