In 1917, the Bolshevik (Russian) Revolution took place and established the Soviet Union. This socialist country helped other countries establish similar governments in countries such as China. The Chinese Revolution of 1949 allowed the communists to take over China since they were backed by the Soviet Union.
Hence, it could be said that the 1917 Russian Revolution and the 1911 Chinese Revolution led to the rise of communist nations during the 20th century.
Hope this was useful. Feel free to ask questions for clarification.
