On 18 January 1871, while Prussia was technically still at war with France, princes from across the German-speaking lands assembled in the Hall of Mirrors at Versailles for a ceremony proclaiming the Prussian king, Wilhelm I, Kaiser of the German Reich. Although the new entity was the first real German nation-state, nobody today, perhaps with the exception of the far right, is celebrating its 150th birthday. In January, Berlin’s Tagesspiegel newspaper called the Second Reich ‘one of the greatest blunders in German history’.

For most Germans, the Second Reich was indeed a gigantic mistake. Its failure to grasp the democratic zeitgeist of the 19th century and its embrace of nationalism and militarism fit the Sonderweg theory of German history, according to which Germany’s ‘special path’ was always going to lead to the Nazis and Auschwitz.

Katja Hoyer, in her excellent and entertaining book Blood and Iron, suggests that it’s all a bit messier than an automatic trajectory to disaster. Hoyer writes that the architect of the empire, chancellor Otto von Bismarck, was no straightforward German nationalist. She casts him as a shrewd diplomat interested in