World War I, also called the Great War, was the most important event of the 20th century. Starting from 1914 and lasting 4 years, the war was the first international conflict involved most of the countries in Europe as well as other regions. Among them, the Central Powers of Germany, Austria-Hungary and the Ottoman Empire fight against the Allied forces of mainly Great Britain, France, Russia and the United States, Italy and Japan later join into the Allied forces later from 1917 one by one. Even though the war ended with the defeat of the central powers, the war resulted in unprecedented casualties and tremendous destruction: by the end of the war in 1918, more than 9 million combatants and 5 million civilians were killed, and more than …show more content…
In June 1914, the archduke visited Sarajevo to inspect the imperial armed forces. Sarajevo, which was now Bosnia and Herzegovina, was occupied and annexed formally by Austria-Hungary after the Ottoman Empire has been pushed out from the Balkans in 1908. But the nationalists in Serbia believed that they should be part of the newly independent nation in Yugoslavia. Thus, Archduke Franz Ferdinand and his wife Sophie were shot by a Serbian-nationalist named Gavrilo Princip, who seek the freedom of Bosnia and Herzegovina under the control of Austria-Hungary Empire. The assassination of Franz-Ferdinand and Sophie caused Austria-Hungary empire blamed the Serbian government for the attack and declared war on Serbia a month later after the assassination. Serbia was a small kingdom, but the Russians ordered a partial mobilization of their troops against Austria in defense of Serbia. As a response, Germany, who allied with Austria-Hungary, after its demands for Russia to halt mobilization met with defiance, Germany declared war on Russia. Russia’s ally, France, ordered its own general mobilization that same day, and later France and Germany declared war on each other. The German army’s planned invasion of neutral Belgium, announced on August 4, prompted Britain to declare war on Germany. Within a week, Russia, Belgium, France, Great Britain and Serbia had lined up against Austria-Hungary and Germany, and World War I had