Acouple of years prior to the centenary of the First World War appeared a work which has transformed public understanding of its outbreak as no other has done since it came to an end, Christopher Clark’s Sleepwalkers.* The tributes it earned, though not quite universal, were overwhelming in register and extent, translations and sales of another order from any previous history of the conflict. All but immediately its title became a catchword for politicians warning of the dangers of any repetition of what had brought the war about, and the need to insure against them. The book that met with this response was the work of a historian born well after the Second World War, in a country that had entered the First World War not as a Great Power, or even an independent participant, but as an auxiliary of the most global of its belligerents. Clark is a descendant, he explains, of a refugee from the Irish famine in colonial Australia.footnote¹ Educated in Sydney, he found his way to the Free University in Berlin in the mid-eighties, then to Cambridge, where he wrote a doctorate on attempts by Protestant missions in Prussia to convert Jews to Christianity; published a biography of Kaiser Wilhelm II in 2000; then a large general history of Prussia from the 17th to the 20th century, Iron Kingdom, in 2006, before producing The Sleepwalkers in 2012. Two years later he was appointed Regius Professor of History of the university, and in 2015 knighted for ‘services to Anglo-German relations’.

Widespread public acclaim—critical or official—is far from a guarantee of worth. In matters intellectual, frequently the opposite. But not invariably, and this is such a case. Ransacking the dictionary, reviewers reached for every plaudit they could find—‘breathtakingly good’, ‘easily the best book ever written on the subject’, ‘monumental’, ‘superb’, ‘revolutionary’, ‘a masterpiece’footnote²—descriptions none of them unjust, if inevitably less than exhaustive of the object enjoying them. By any measure, The Sleepwalkers is a great work of history. What sets it apart within the literature on the First World War that now stretches back for over a hundred years, and continues to accumulate with little sign of dwindling, are five achievements. First and foremost is the sheer range of its coverage, encompassing in a single volume not only the full Pentarchy of Great Powers which plunged into the war—which was, after all, game too for Fay and Schmitt at the outset of its historiography—together with Serbia, subject to extended scrutiny by Albertini, but drawing on a much wider body of evidence and argument about its onset than ever before. The condition of that range is a polymathic ease in the languages of Europe beyond the scope of any precursor, yielding a command of sources—primary and secondary—not just in French, German, Italian and Russian, but Serbo-Croatian, Polish and Dutch to boot.

Married to depth of scholarship is pace of narrative. The interactive complexity of Europe’s descent into war, involving rival states all prey to internal divisions as they lurched towards the battlefield, has tended to render a clear account of it formally intractable. Clark handles the problem with brio, to such effect that the book was from the start a best-seller. At the same time, cross-cutting the story is an analytic of power and rule that, as Clark would have it, set the parameters for the political actors of the period. Narration and reflection, often at variance with each other in writing about the past, find an ingenious resolution in the structure of the book. The first hundred pages consider the contrast between the two states whose antagonism detonated the war, Serbia and Austro-Hungary, followed by a hundred and fifty on the surrounding polarization of Europe into rival armed camps, the divisions within each of the regimes that came to belong to the two blocs, and the way these forces escalated tensions in the Balkans; before finally reverting to the assassination of the heir to the Habsburg empire in Sarajevo that set off the crisis of July 1914, and countdown to the Great War. The movement of the book from the diachronic to the synchronic, and back to the diachronic again, is executed with confident literary skill. Last but not least, a notable feature of The Sleepwalkers is the equity of its judgments across a field where so many of even the best scholars have been unable to detach themselves from the passions of the countries where they were formed, or the convictions of the powers superintending them. Distance of geography and of generation from the scene of the disaster has obviously played a role in Clark’s freedom from these weaknesses, permitting for the first time a level-headed treatment, critical without saving clauses or special pleading, of all the European powers that took to arms in 1914. Each emerges in a new light from his account.

The most arresting single novelty of The Sleepwalkers comes in its opening chapter, devoted to Serbia, regularly marginalized or ignored in much of the literature on the origins of the First World War. Here it receives an extended socio-political account from the overthrow of the Obrenović dynasty in 1903 to the eve of the conflict in 1914, throwing into relief the character of its peasant society, the popular legends of its past, the dominance of the Radical party in its parliamentary system, the countervailing influence of the Army in national life, and the expansionist dynamic of the country, powered by both of these forces. Such, Clark shows, was the background to the foundation in 1911 of Union or Death, the conspiratorial network of the ‘Black Hand’ spanning military and civilian recruits and blurring the boundaries between official and unofficial activities in Serbia, whose most effective leader was the regicide officer ‘Apis’. It was in this milieu that a trio of Bosnian boys was trained and armed in Belgrade, and assured clandestine passage across the frontier to Sarajevo for the assassination of the Archduke Franz Ferdinand. The Serbian government was aware of their movement—its premier, the Radical veteran Nikola Pašić, noted the news over a month before the killings occurred, connecting it with the name of a well-known operative of the Black Hand.footnote³ Though Pašić and Apis were enemies in domestic politics, they shared the irredentist goal of a Greater Serbia, and there was as yet no open conflict between the two. It was under Pašić, later responsible for his judicial murder, that Apis was appointed director of military intelligence with responsibility for monitoring the country’s borders.

Across these to the north and the west lay the Habsburg domains, dubbed Musil-style by Clark—on his own showing, not so appositely—‘the Empire without Qualities’. Though not as minimized as Serbia in standard accounts of the origins of the Great War, the Dual Monarchy would be generally misrepresented by them as a backward, disorganized and incompetent laggard in the comity of major European powers. The reality, Clark contends, was otherwise. True, the Ausgleich of 1867 had split the empire into two separate realms, each possessing its own executive, legislature and judiciary, with little political contact between the two, each dominated by an ethnic group which was numerically the largest, but still a minority of the population in its territory. In the Hungarian parliament a highly restrictive suffrage ensured effortless Magyar control over Croats, Romanians and lesser breeds. In the Austrian, after 1906 elected by universal male suffrage, every significant nationality—Czechs, Poles, Italians, Ruthenians and others, along with Austrians themselves—was represented, disputes between them paralysing proceedings. To that extent, political life was dysfunctional. But above the juridical sundering and ethnic quarrels of the Habsburg lands, the state was held quite firmly together by three unitary pillars under the direct control of the ruling dynasty: the army, treasury and diplomacy, whose ministers of war, finance and foreign affairs were appointed by the emperor and vested with pan-territorial powers. It was the first two of these institutions at the top of the system which ensured order and progress within it.

On both scores, Clark argues, the late record of the Dual Monarchy was quite impressive. Unlike Tsarist Russia, it was a Rechtsstaat that offered civic freedoms and predictable justice to its subjects; peace and quiet without revolutionary upheavals or violent disorder; not to speak of a famous flowering of cultural life. Economically and educationally, far from bringing up the rear of the Pentarchy, it was in some surprising respects in the vanguard of the time, posting one of the fastest growth rates in Europe and higher enrolment in elementary schools than France or Germany, let alone Italy or Russia. Heavy industry was booming, agricultural exports rising, the railway network expanding. Even in Bosnia—long administered, if only recently annexed, by it—Habsburg rule had brought investment, urbanization and a certain measure of modernity.footnote⁴ Unrest in different degrees among allogenous nationalities there was, across the empire. But Bosnia aside, where there were as yet no elections, the development of what was becoming the normal spectrum of political parties in Western Europe—a conservative right, a liberal centre, a social-democratic left—acted as a stay against radicalization of breakaway nationalism, since it divided rather than incentivized ethnic groups: intransigent secessionism still looked relatively weak. But regionally, the Habsburg Empire was on the defensive rather than offensive. In 1909 it had annexed Bosnia to secure the province against any knock-on effect of the Young Turk revolution, only to find itself an impotent witness in the First Balkan War of the end of Ottoman power in Europe, and in the Second a doubling of the size of Serbia—whose expansionists like to picture the country as a dagger thrust into the belly of Austro-Hungary—together with the defection of Romania from nominal alliance with the Central Powers. In the wake of these setbacks, mounting fears and fancies gripped Vienna, personified in the antithetical figures of the (temperamentally) languid Berchtold, in charge of foreign policy, and the (perpetually) fire-breathing Conrad of the army, now united in a resolve to meet any new threat with force.

At sixty pages apiece, Serbia and Austro-Hungary receive more detailed and consolidated scrutiny than any of the other belligerents, none of whom earn comparable treatment of their internal politics. In the years before the Great War the roles of France, Germany, Russia and England are viewed essentially through the prism of their foreign policies, broken up into smaller segments distributed across successive chapters—an asymmetry no doubt due in part to the requirements of setting the stage for the main action, perhaps too as better covered in the existing literature. The second part of the book opens with the birth of the Franco-Russian alliance in the early 1890s; the origins of the Entente Cordiale of 1904 between France and Britain; the contrasting position of Germany as a belated entrant into the imperial club they formed; the reasons for the hostility its arrival aroused in Britain; and for Clark, a ‘great turning-point’ in Europe with the signature of the Anglo-Russian Convention of 1907, which completed a polarization of the continent into two camps.footnote⁵ The next chapter looks at the ways power was less than unified within all the major states of the time, in a vivid survey of the divisions and confusions in the executive of each—random interventions by assorted monarchs, lack of collegiality in cabinets, bureaucratic intrigues, frictions between military and civilian personnel, background noise of rising mass parties and excitable press campaigns. In this unsettled atmosphere, Clark suggests, there came an alteration in the mentality of power-holders and those around them: not so much outright bellicism as a ‘deepening readiness for war’.footnote⁶