What led to the Great War?

Continual trouble in the Balkans led to the formation of several complicated military alliances throughout Europe. The continent was eventually split into two groups. Britain, France, and later Russia joined to form the Entente Cordiale; Germany, Austri-Hungary and Italy formed the Triple Alliance. In 1914 Archduke Franz Ferdinand of Austria-Hungary was assassinated in Serbia, activating the alliance agreements. First Austria declared war on Serbia, Russia sided with Serbia, and then Germany declared war on Russia. Germany invaded Belgium, bringing the British and French into the conflict. The British, French and Russians became known as the Allies, while their opponents were the Central Powers.

World War I, or the Great War, was the first mechanized war in history. In the beginning, the fighting was similar to wars fought during the previous century. Mounted cavalry charged enemy lines but were cut down by fire from the recently developed machine guns. No modern tactics had been developed to handle the battles between armies spread across whole countries.

The battlefields became deadlocked, with few advances. The troops dug deep trenches. About 10 million men died in battles, which usually gained an advance of about one kilometer. Another 20 million men were wounded.