The First World War of 1914-18 affected nearly every family in Britain, as well as those whose homes were in distant parts of what was then the British Empire, such as Canada, Australia and New Zealand. All came together in a common cause and most endured a common suffering. In recent years there has been unprecedented interest in tracing the careers of soldiers who fought in the Great War. This arises partly from family history researchers taking advantage of the internet and improved access to research archives, and to recognition by them of the cataclysmic nature of the war that should have ended all wars. Many family historians possess photographs from that era, usually of young, eager boys in their first uniforms. But so many are anonymous and they carry no detail of the sitter's Regiment or Corps. This book presents a simple, illustrated guide to the badges that help identify this core information about a First World War ancestor, whether it is a basic cap badge, collar badge, arm, rank, service and proficiency badges or particular items of regimental dress.