The policy of extending a country’s influence over less powerful states. Historically imperialism has existed in all periods: Greece, Rome, Ottoman Turkey, Spain, and Britain have all extended their respective domains by imperial rule. The Industrial Revolution introduced a new form of imperialism as European countries competed throughout the world both for raw materials and for markets. In the late 19th century imperial ambitions were motivated in part by the need for commercial expansion, the desire for military glory, and diplomatic advantage. Imperialism generally assumed a racial, intellectual, and spiritual superiority on the part of the newcomers. The effects of imperialism, while in some measure beneficial to the subjected population, often meant the breakdown of traditional forms of life, the disruption of indigenous civilization, and the imposition of new religious beliefs and social values. The dreams of imperialism faded in the 1920s as anti-imperialist movements developed, and from the 1940s many colonies gained their independence.