The first attempts to introduce blood transfusion into battlefield surgery were made in the 1860s and 1870s when the lack of coordination in the actions of army leaders and the unpreparedness of the military medical service meant that thousands of wounded soldiers died on the battlefield while awaiting medical assistance. The use of blood transfusion began with the Franco-Prussian War of 1870‒1871. In the post-war period, military doctors had a wide choice of transfusion methods, and of tools and fluids (whole or defibrinated animal or human blood, normal saline, etc.) used for this purpose. The attempt to introduce blood transfusion into battlefield surgery in the mid-1870s was based not just on experimental and clinical data that gave hope of reviving and giving strength to the wounded, but also on the practical possibility of finding a suitable donor on the field of combat. The most promising methods appeared to be the transfusion of whole blood — human, obtained from fellow soldiers or assistants in the medical service (using a method pioneered by Joseph-Antoine Roussel) and animal (using a method pioneered by Franz Gesellius). For advocates of interspecies transfusion, the practical convenience of using animals as a living blood bank for transfusions for multiple patients outweighed the physiological data on the advantages of intraspecies transfusions. Even so, whole blood transfusions were not common in military medicine in the last quarter of the nineteenth century, mainly because not enough was known about blood physiology. © MS Sergeeva, EL Panova.