First World War is considered as one of the largest wars in history. The world's great powers assembled in two opposing alliances the Allies (British Empire, France and the Russian Empire) versus the Central Powers (Germany and Austria-Hungary). WWI lasted from 28 July 1914 to 11 November 1918. Over the course of the 19th century, rival powers of Europe formed alliances. Germany, Austria-Hungary, and Italy formed the Triple Alliance. Great Britain, France, and Russia formed the Triple Entente.

more »

... ensions grew between Austria-Hungary and Serbia as Serbian nationalists attempted to unite all Slavic peoples living in the Balkan region into a single state, including South Slavs of Austria-Hungary. German success in the Franco-German War established the German Empire. Germany's takeover of Alsace-Lorraine created a desire for revenge by the French. The assassination of Austrian Archduke Franz Ferdinand and his wife by Bosnian Serb nationalist Gavrilo Princip on June 28, 1914, suddenly stirred up brewing conflicts in the region. Austria- Hungary used the assassination as an excuse to settle its dispute with Serbia. In anticipation of Russia's support of Serbia, Austria-Hungary gained support from William II of Germany before presenting a warlike ultimatum to Serbia. Serbia accepted most of Austria-Hungary's demands but sought international arbitration on some issues. Convinced that Austria-Hungary was ready for war, Serbia appealed to Russia for support. Austria- Hungary severed diplomatic relations with Serbia, and, on July 28, 1914, declared war on Serbia. Within a week most of Europe was at war.