The war that would destroy European society had been coming for a long time. The nineteenth century had been an era of great progress,and of turmoil and conflict as well. New nations had been created. The balance of power that existed in 1815, at the end of the era of Napoleon, was disturbed. Adding to the danger was a false sense of security. Local wars had flared up in the nineteenth century, but a major war was regarded as unlikely. Looking back at 1914 today, however, we can see that each of the major countries of Europe had interests that would bring it into conflict with at least one of the other great powers.
On June 28, 1914, Gacrilo Princip, a nineteen-year-old Serbian revolutionary, fired two pistols shots. One killed Archduke Franz Ferdinand, the nephew of Emperor Franz Joseph of Austria-Hungary and heir to the Austrian throne. The other killed Sophie, his wife.Austria-Hungary held Serbia responsible. On July 5 Austria asked for and recieved from Germany a "blank check" of support for any action Austria-Hungary might take against Serbia.On July 23 Austria sent a series of demands to the Serbians. The demands were designed to humiliate and virtually destroy the Serbian nation. Still, Serbia agreed to most but not all of the demands.Austria reacted on July 28 by declaring war on Serbia. The Russians prepared to defend Serbia. On July 31 the Germans sent a warning to Russia to stop mobilizing its army for war. the Russians ignored the warning, and Germany declared war on Russia on August 1. France came to the aid of its Russian ally by declaring war on Germany. The British hesitated, but when the Germans marched into Belgium, they declared war on Germany on Aug 4.