

In 1917, two events changed the course of the war: the United States joined the Allies and Russia, after the Russian revolution, abandoned the conflict and signed a separate peace.Meanwhile on the Eastern Front the Germans advanced but not decisively. After a brief German advance in 1914, the western front was stabilized and a long and brutal trench warfare started: it was a "war of attrition" (the western front remained immovable).The second front was the Eastern front in which the Russians fought against Germans and Austro-Hungarians. The two main scenarios were the Western front, where the Germans confronted Britain, France and, after 1917, the Americans. The conflict developed on several fronts in Europe, Africa, and Asia.Some of the major battles during the war included the First Battle of the Marne, Battle of the Somme, Battle of Tannenberg, Battle of Gallipoli, and the Battle of Verdun.Britain declared war on Germany because of its invasion of neutral Belgium - Britain had agreements to protect both Belgium and France.Germany then declared war on Russia because Germany had an alliance with Austria-Hungary.Russia got involved as it had an alliance with Serbia.Because its leader had been shot, Austria-Hungary declared war on Serbia.

He was killed by a Serbian person, who thought that Serbia should control Bosnia instead of Austria. Assassination of Archduke Franz Ferdinand: In June 1914, Archduke Franz Ferdinand, the heir to the throne of Austria-Hungary, was shot while he was visiting Sarajevo in Bosnia.Nationalism: Much of the origin of the war was based on the desire of the Slavic peoples in Bosnia and Herzegovina to no longer be part of Austria Hungary but instead be part of Serbia.This increase in militarism helped push the countries involved into war. Great Britain and Germany both greatly increased their navies in this time period. By 1914, Germany had the greatest increase in military buildup. Militarism: As the world entered the 20th century, an arms race had begun.The increasing competition and desire for greater empires led to an increase in the confrontation that helped push the world into World War I. Imperialism: Before World War I, Africa and parts of Asia were points of contention among the European countries because of their raw materials.Thus, there were two rival groups in Europe.įig: Alliances at the beginning of the War.

