Until not so very long ago Wilhelm II was dismissed as a Schattenkaiser, a shadowy figure without power and of little historical significance. The man who, as German emperor, King of Prussia and Supreme War Lord, ruled for thirty years (from 1888 to 1918) over the mighty Prusso-German Reich, at the heart of Europe, was largely ignored by German historians. None of them paid serious attention to this grandiloquent, sabre-rattling monarch with the provocative moustache in his shimmering eagle-helmeted uniform, who sacked Prince Bismarck, the founder of the German Reich, in 1890, built up a gigantic battlefleet against Britain, and in 1914 led his flourishing empire into the First World War. One does not need to be a Sherlock Holmes to get to the bottom of this startling omission: as treacherous as the silence pervading The Hound of the Baskervilles, the taboo imposed on all mention of Wilhelm II during the Weimar Republic and the Nazi era was part of the campaign in German historiography to reject the ‘war guilt lie’ of Versailles. In the last three decades, however, our understanding of Kaiser Wilhelm II’s place in German history has gained infinitely more depth. His flawed personality, his angry view of the world, his autocratic methods as ruler and his ambitious naval and world power policies now stand at the heart of a lively debate over continuity and disruption in the history of the first German nation state from 1871 to 1945. Biographies saturated with new archival evidence have appeared, together with volumes of documents running to a thousand pages, scholarly editions of his speeches, monographs on his relationship with the armed forces and with religion, art, science, film and the world of industry and technology, and psychological and socio-anthropological examinations of his circle of friends or the scandal-ridden Hohenzollern court; all these subjects have been put under the microscope. True, there is still work to do – very little attention has been paid to the evidence on Wilhelm in the Russian and French archives, for instance – and no general consensus has yet been reached: Wilhelm II continues to divide opinion.