World War I was the peak of a long era of conflict and revolution. You have already read about political and industrial revolutions that rocked the world in the 1700s and 1800s. In the early 1900s, while the "Great War" still raged, yet another revolution broke out--in Russia. The Russian Revolution was an extremely important event in modern world history.
In 1900 the Russian empire stretched across parts of Europe and Asia. It included people of many different cultures. Most, though, lived in western Russia, where the land was better suited for the empire's main activity--farming. Most Russians were Christians. Muslims also lived in the empire, however, as well as many Jews.
World leaders took notice when revolutionaries overthrew Russia's leaders in 1917. Revolutionary leaders began to build a government around the ideas of Karl Marx, whom you read about in Chapter 17. The world watched and waited. What would happen in Russia? Would Russia continue to fight in World War I? How would the revolution affect other nations?