For several decades during the 20th century, communism was one of the world's dominant forms of government. At one time, Communist regimes held power across much of Asia and all of Eastern Europe. In addition, Cuba and a handful of countries in Africa had Communist governments. Leading the Communist bloc was the Soviet Union, a superpower whose global influence rivaled that of the United States. By the early 1990s, however, communism had collapsed in the Soviet Union and its satellite countries in Eastern Europe. Today only China, Vietnam, North Korea, and Cuba continue to be ruled by Communist regimes. This book provides an introduction to communism. It explores the principles that underpin communism and examines the way Communist governments have exercised power in practice.