The centenary of the start of the First World War has stirred considerable interest in the political, social, military and human factors of the time and how they interacted to produce and sustain the material and human destruction in the 4 years of the war and beyond. Medical practice may appear distant and static and perhaps seems to have been somewhat ineffectual in the face of so much trauma and in the light of the enormous advances in medicine and surgery over the last century. However, this is an illusion of time and of course medical, surgical and psychiatric knowledge and procedures were developing rapidly at the time and the war years accelerated implementation of many important advances. Transfusion practice lay at the heart of resuscitation, and although direct transfusion from donor to recipient was still used, Geoffrey Keynes from Britain, Oswald Robertson from America and his namesake Lawrence Bruce Robertson from Canada, developed methods for indirect transfusion from donor to recipient by storing blood in bottles and also blood-banking that laid the foundation of modern transfusion medicine. This review explores the historical setting behind the development of blood transfusion up to the start of the First World War and on how they progressed during the war and afterwards. A fresh look may renew interest in how a novel medical speciality responded to the needs of war and of post-war society.