Over the course of five days, beginning August 25, 1914, German troops stationed in the Belgian village of Louvain during the opening month of World War I burn and loot much of the town, executing hundreds of civilians.

Located between Liege, the fortress town that saw heavy fighting during the first weeks of the German invasion, and the Belgian capital of Brussels, Louvain became the symbol, in the eyes of international public opinion, of the shockingly brutal nature of the German war machine. From the first days they crossed into Belgium, violating that small country’s neutrality on the way to invade France, German forces looted and destroyed much of the countryside and villages in their path, killing significant numbers of civilians, including women and children. These brutal actions, the Germans claimed, were in response to what they saw as an illegal civilian resistance to the German occupation, organized and promoted by the Belgian government and other community leaders—especially the Catholic Church—and carried out by irregular combatants or franc-tireurs (snipers, or free shooters) of the type that had participated in the Franco-Prussian War in 1870-71.

In reality this type of civilian resistance—despite being sanctioned by the Hague Conventions of 1899 and 1907, which the Germans objected to—did not exist to any significant degree in Belgium during the German invasion, but was used as an excuse to justify the German pursuit of a theory of terror previously articulated by the enormously influential 19th-century Prussian military philosopher Karl von Clausewitz. According to Clausewitz, the civilian population of an enemy country should not be exempted from war, but in fact should be made to feel its effects, and be forced to put pressure on their government to surrender.

The burning of Louvain came on the heels of a massacre in the village of Dinant, near Liege, on August 23, in which the German soldiers had killed some 674 civilians on the orders of their corps commander. Two days later, the small but hardy Belgian army made a sudden sharp attack on the rear lines of the German 1st Army, commanded by General Alexander von Kluck, forcing the Germans to retreat in disorder to Louvain. In the confusion that followed, they would later claim, civilians had fired on the German soldiers or had fired from the village’s rooftops to send a signal to the Belgian army, or even to approaching French or British troops. The Belgians, by contrast, would claim the Germans had mistakenly fired on each other in the dark. Whatever happened did not matter: the Germans burned Louvain not to punish specific Belgian acts but to provide an example, before the world, of what happened to those who resisted mighty Germany.

Over the next five days, as Louvain and its buildings—including its renowned university and library, founded in 1426—burned, a great outcry grew in the international community, with refugees pouring out of the village and eyewitness accounts filling the foreign press. Richard Harding Davis, an American correspondent in Belgium, arrived at Louvain by troop train on August 27; his report later appeared in the New York Tribune under the headline GERMANS SACK LOUVAIN; WOMEN AND CLERGY SHOT. A wireless statement from Berlin issued by the German Embassy in Washington, D.C., confirmed the incidents, stating that “Louvain was punished by the destruction of the city.” The Allied press went crazy, with British editorials proclaiming “Treason to Civilization” and insisting the Germans had proved themselves descendants not of the great author Goethe but of the bloodthirsty Attila the Hun.

By war’s end, the Germans would kill some 5,521 civilians in Belgium (and 896 in France). Above all, German actions in Belgium were intended to demonstrate to the Allies that the German empire was a formidable power that should be submitted to, and that those resisting that power—whether soldier or civilian, belligerent or neutral—would be met with a force of total destruction. Ironically, for many in the Allied countries, and in the rest of the world as well, a different conclusion emerged from the flames of Louvain: Germany must be defeated at all costs, without compromise or settlement, because a German victory would mean the defeat of civilization.

READ MORE: Life in the Trenches of World War I