Chapter one explores the very specific role the architects, leaders and volunteers of the International Brigades assigned themselves within the wider loyalist war effort, arguing that they became one of many interest groups keen to shape the antifascist struggle in their own image. Their ubiquitous claim to be bringing desperately-needed reserves of unity, order and discipline to the Republican cause owed much to the transnational attitudes of the unitߣs members as well as their more immediate links to the Communist Party and its armed Fifth Regiment. This self-assigned mission was internalised by many of the volunteers on the basis of their military training, trench press and experiences of combat, going on to shape their attitudes towards other groups fighting against Franco. In spite of an underlying rhetoric of antifascist unity, the volunteersߣ understanding of their place in Spain inspired mixed responses from their allies. By uncovering the creation and reception of the International Brigadesߣ military culture, this opening chapter restores the famous fighting force to the wider social, political and military context which underpins the rest of the book.