War was Britain’s furnace for two thousand years and we are that forging. Rome conquered England if not Scotland and imposed military rule. Saxon raiders, then Vikings and finally Normans each invaded in turn. England and Scotland spent three hundred years at war with each other – a very nasty form of endemic, asymmetric warfare – and those scars still linger. Edward III pursued expeditionary warfare against France and established a tradition that has since characterised UK military activity: the projection of force across the globe, as recently demonstrated in the Falklands War of 1982. In 1914 Lord Haldane asked: ‘What is the Army for?’ Nobody yet has a definitive answer, nor ever will. All of this experience and the many traditions it has fostered are preserved in our military museums, the broad threads of history and grand strategy but also the human dimension of individual stories. Author John Sadler, in the company of Captain Graham Trueman, formerly of 3rd Battalion The Light Infantry, visited over fifty museums to tell those stories here. The museums cover the whole of Britain, from the King’s Own Scottish Borderers Museum, Berwick upon Tweed, to the Spitfire and Hurricane Memorial Museum, Ramsgate. Emerging global threats have thrown into stark relief the need to determine the role of the UK’s armed forces and its global aspirations in an unstable world. To ascertain how we move forward, we need to understand what went before. Leon Trotsky warned that ‘You may not be interested in war, but war is always interested in you…’