The kings who ended Europe’s long peace a century ago knew not that the Great War would mean their end too. The First World War was the end of monarchial rule on the continent. The proximate cause of war in the summer of 1914 was regicide — the assassination of the Archduke Franz Ferdinand and the Archduchess Sophie, heirs to the Habsburg throne with its astonishing array of imperial and royal titles, including that of the Holy Roman Empire. Indeed, the ferocity of Austria-Hungary’s response to the assassination was defended by its allies in Germany as a fitting response to regicide, which undermines the whole of the social order. 

While democracy had steadily been gaining ground in the 18th and 19th century, the emperor in Vienna, the kaiser in Berlin and the tsar in Moscow were all real kings holding real power. In London and Brussels the kings were influential but constrained by parliament, and in France and Italy the thrones had been deposed. By the end of the war, Kaiser Wilhelm II was in comfortable exile, having abdicated, in the Netherlands, Emperor Charles of Austria was in penurious exile, having been stripped of his throne, and Tsar Nicholas and his family had been killed by the Bolsheviks. The Great War was bloody on the battlefield; it was lethal for Europe’s royal houses.