World War I

In the late 1800s and early 1900s rivalries between European powers began to intensify. Imperialist states were fighting over land in Asia and Africa, ethnic groups were struggling for self-control, and nations were competing to build larger and more powerful military forces. In addition the region had developed a system of alliances in which nations would help each other out in disputes.

In 1914 a Serbian nationalist shot and killed the heir to the Austro-Hungarian throne, which proved to be the spark that set off World War I. As tensions mounted between Austria-Hungary and Serbia, Germany (which was allied with Austria-Hungary) declared war on Russia (which was allied with Serbia). Germany expanded the conflict when it declared war on France and marched into Belgium to reach France, thus breaking an 1839 neutrality agreement. Great Britain declared war on Germany that same day. Other nations joined the fray...