History: The Nazis, declared their propaganda chief, Josef Goebbels, in 1932, "can justly lay claim to Prussiandom.
All over Germany, wherever we stand, we are Prussians. The idea we carry is Prussian. The symbols for which we fight are filled with the spirit of Prussia, and the objectives we hope to achieve are a renewed form of ideals for which Frederick William I, Great Frederick and Bismarck once strove". With advocates like that, who needs enemies? No wonder then, with Nazi Germany defeated, the victorious allies promptly abolished Prussia after the war.
That the Nazis embraced Prussia's past so enthusiastically has made studying its history a complex business. Law No. 46 of the Allied Control Council, which expunged Prussia, noted that the state had "from early days been a bearer of militarism and reaction in Germany". The decision to abolish the state, "together with its central government and all its agencies", was "guided by the interests of preservation of peace and security of peoples, and with the desire to assure further reconstruction of the political life of Germany". Churchill, typically, had put it more pithily a few years earlier. "The core of Germany is Prussia," he told the House of Commons in 1943. "There is the source of the reoccurring pestilence." Eradicating Prussia from the map of Europe was thus a political necessity after the second World War. "Its history had become a nightmare that weighed upon the minds of the living," writes Christopher Clark in Iron Kingdom.
For most of its existence, however, the history of Prussia had been seen in a more positive light. Protestant historians in particular celebrated the state as a vehicle of rational administration and progress, not to mention as the liberator of Germany from the tentacles of Habsburg Austria and Napoleon's France. Prussia's success in uniting the German states in 1871 was celebrated as the natural and best possible outcome to a German evolution that had started with the Reformation.
It was not until the 1960s - when the Berlin Wall became a focus of the cold war - that post-second World War historians, mainly conservatives from West Germany, attempted to shake off the taint of Nazism and restore an older assessment of Prussian history. Not only did they emphasise its positive achievements - an incorruptible and highly efficient civil service, tolerance of religious minorities (including Jews), a code of law (from 1794) that was admired and imitated throughout the German states, and the highest literacy rates in Europe - they stressed the role played by many Prussians in attempting to undermine the Nazi regime, not least the attempt to assassinate Hitler in 1944. Much of the reaction to this exercise in revisionism was hostile.
Even in post-unification Germany, the battle for Prussia's historical and symbolic legacy remains a hot topic. A centre-left deputy in the Brandenburg state government won instant notoriety in 2002 for his intervention in a debate on the proposed merging of the city of Berlin with the federal state of Brandenburg. "Berlin-Brandenburg", he said, was too cumbersome. Why not just call the new territory "Prussia"? National pandemonium ensued.
All of which makes Christopher Clark's task in writing a new history of Prussia an exercise in juggling political, historiographical and emotional incendiary devices. His approach to writing a balanced history of the state turns out to be practical and empirical. He spurns any attempt at "teasing out the virtue and vice in the Prussian record" or to dispense moral or political advice to present or future generations. Rather, he tells us with a touch of self-deprecation, "as an Australian historian writing in twenty-first century Cambridge, I am happily dispensed from the obligation (or temptation) either to lament or to celebrate the Prussian record. Instead, this book aims to understand the forces that made and unmade Prussia". The result, Iron Kingdom, is a triumph of scholarship and imagination. This is a big book in every sense - at almost 800 pages, it's not one to slip in your briefcase for the train - but it zips along in a manner that belies its weight. In part this is because Clark writes so elegantly. This is history in its "grand sweep", but his vivid sketches of characters, places and events lighten the narrative. Yet for all its entertainment value, Iron Kingdom is at heart an unflinching engagement with one of Europe's most complex and far-reaching political and cultural entities, spanning four centuries of history and, he suggests at the end, even beyond.
The story takes us from the early origins of Prussia and the capital, Berlin, as an impoverished medieval backwater to its transformation by the Hohenzollerns into one of the most dynamic powers in Europe. The great figures, of course, are here - Frederick the Great, Moses Mendelssohn, Bismarck, and the rest - along with the important iconic events and movements - the age of enlightenment, the Wars of Liberation and the creation of the "Iron Cross". These all emerge fresh minted thanks to Clark's broad perspective and layer upon layer of nuanced detail.
The crucial turning point in Prussia's destiny, however, comes (as so often) at the moment of its greatest glory. Unification of the German states by the Hohenzollerns was the apotheosis of Prussian leadership, but it also presented them with new influences and problems that they struggled to master. Berlin "had to learn to inhabit the large and ponderous body of the new Germany", writes Clark, "The demands of German nationhood complicated the inner life of the Prussian state, amplifying its dissonances, disturbing its political equilibrium, loosening some bonds while reinforcing others, bringing at once a diffusion and a narrowing of identities". Prussia, not to mention Europe, would have been better off had they just stuck to "Ich bin ein Berliner".
Richard Aldous teaches history at UCD. His latest book, The Lion and the Unicorn: Gladstone vs Disraeli, will be published by Hutchinson in October
Iron Kingdom: The Rise and Downfall of Prussia, 1600-1947 By Christopher Clark Penguin Allen Lane, 777pp. £30