During 1914-1918, World War I raged across Europe's Western and Eastern Front. With trench warfare, airplanes, and submarines, battles were bloody and cost millions of lives. Conditions were brutal and there were very few decisive victories. This guide hi
Historians believe that several events triggered World War I. Many countries wanted to maintain their colonial empires and extend their imperial conquests. Other countries tried to shift powers, so hostile alliance systems existed.
