Drawing heavily on original material - letters, diaries, official papers - Simon Heffer's hugely ambitious new book follows Britain's path from the day the fatal shots were fired at Sarajevo in June 1914 to the moment the guns finally fell silent on 11 November 1918. He painstakingly examines the increasingly frantic conversations between Whitehall and Britain's embassies across Europe as civil servants and ministers sought to understand and control the slide towards war. He explains how a government so keen to avoid conflict found itself not only championing it but seeking to transform the country to fight it - and how, in the process, Britain was irrevocably changed. He looks at the high politics and low skulduggery that saw the principled but passive Asquith replaced as Prime Minister by the unscrupulous but energetic Lloyd George, and he assesses the furious arguments between politicians and generals about how best to prosecute the war that persisted until the final offensive on the Western Front. And he considers the impact of the First World War on everyday life as people sought to cope with dwindling stocks of food and essential supplies, with conscription into the army or wartime industries, with the ever-present threat of family loss and, in Ireland, with the aftermath of the Easter Uprising. Throughout he creates vivid portraits of the era's key protagonists - from Lord Kitchener to Winston Churchill and from the pacifist Lady Otteline Morrell to the press magnate Lord Northcliffe - building a rich and varied account of a period in which Britain's very existence seemed in question.