March 23

The terrible conflict of World War I lead to the Russian Revolution and the beginning of world communism. The most recent period of world history has probably ended with the Soviet Union collapsing in 1991, and with the attacks of September 11, 2001. European rivalries around the globe have been going on for centuries. The Russian and Chinese revolutions were the first large-scale attempts in modern world history to create a new and global division of humankind. Feminism became global in the twentieth century, and challenged women's subordination more extensively than ever before. Explosive population growth lead to human numbers more than quadrupling since 1900, thus the planet had about seven billion people by 2011.