Communism, born of the Russian Revolution of 1917, subsequently took root in Eastern Europe, China, Southeast Asia, and Cuba, providing the governing ideology for roughly one third of the world's population by the 1970s. In the Holocaust, the Soviet terror of the 1930s, the Chinese Great Leap Forward and Cultural Revolution, and Cambodia's 'killing fields', communism and fascism generated human tragedies on an immense scale. Ideologies consist of ideas and values about public life, understandings as to how society works or ought to work, and contain both views of history and visions of the future. Such ideologies provided the foundation for social movements, usually embodied in a political organization or a party. In places where movements became regimes, fascists and communists alike had the opportunity to put their ideologies into practice. The effective end of communism occurred very differently from fascism. Its economic and moral failures had eroded support among both elites and ordinary people while generating movements of reform.