Christopher Clark, an Australian-born Cambridge historian, provides a riveting account of the July Crisis of 1914 that led to World War I. Rather than assigning blame to any single nation or leader, Clark traces the interlocking decisions that transformed the assassination of Archduke Franz Ferdinand into a continental catastrophe. The book follows the key actors through Vienna, Berlin, St. Petersburg, Paris, London, and Belgrade, showing how each government responded to events with incomplete information and competing pressures. Clark examines the decades of diplomatic history that created the conditions for crisis, including the alliance systems, the arms races, and the accumulated grievances that made war thinkable. He pays particular attention to the Balkans, showing how the region's complexity and the great powers' entanglement in local conflicts created a tinderbox. Clark's metaphor of 'sleepwalkers' suggests that the participants stumbled into catastrophe rather than choosing it deliberately, though he acknowledges the militarism and nationalism that made such stumbling possible. The book has influenced subsequent debate about responsibility for the war while remaining accessible to general readers. Essential reading for understanding how a political assassination triggered the collapse of the old European order and the catastrophes of the twentieth century.