In political science, a revolution (, 'a turn around') is a fundamental and relatively sudden change in political power and political organization which occurs when the population revolts against the government, typically due to perceived oppression (political, social, economic) or political incompetence. Revolutions have occurred throughout human history and vary widely in terms of methods, duration, and motivating ideology. Their results include major changes in culture, economy, and socio-political institutions, usually in response to perceived overwhelming autocracy or plutocracy. Scholarly debates about what does and does not constitute a revolution center on several issues. Early studies of revolutions primarily analyzed events in European history from a psychological perspective, but more modern examinations include global events and incorporate perspectives from several social sciences, including sociology and political science. Several generations of scholarly thought on revolutions have generated many competing theories and contributed much to the current understanding of this complex phenomenon. Notable revolutions in recent centuries include the creation of the United States through the American Revolutionary War (1775–1783), the French Revolution (1789–1799), the Haitian Revolution (1791–1804), the Spanish American wars of independence (1808–1826), the European Revolutions of 1848, the Russian Revolution in 1917, the Chinese Revolution of the 1940s, the Cuban Revolution in 1959, the Iranian Revolution in 1979, and the European Revolutions of 1989. Etymology The word "revolucion" is known in French from the 13th century, and "revolution" in English by the late fourteenth century, with regard to the revolving motion of celestial bodies. "Revolution" in the sense of representing abrupt change in a social order is attested by at least 1450. Political usage of the term had been well established by 1688 in the description of the replacement of James II with William III. This incident was termed the "Glorious Revolution". Types There are many different typologies of revolutions in social science and literature. Alexis de Tocqueville differentiated between: political revolutions, sudden and violent revolutions that seek not only to establish a new political system but to transform an entire society, and; slow but sweeping transformations of the entire society that take several generations to bring about (such as changes in religion). One of several different Marxist typologies divides revolutions into: pre-capitalist early bourgeois bourgeois bourgeois-democratic early proletarian socialist Charles Tilly, a modern scholar of revolutions, differentiated between; coup d'état (a top-down seizure of power) civil war revolt, and "great revolution" (a revolution that transforms economic and social