The people of India have had a continuous civilization since 2500 B.C., when the inhabitants of the Indus River valley developed an urban culture based on commerce and sustained by agricultural trade. This civilization declined around 1500 B.C., probably due to ecological changes.
The first British outpost in South Asia was established in 1619 at Surat on the northwestern coast. Later in the century, the East India Company opened permanent trading stations at Madras, Bombay, and Calcutta, each under the protection of native rulers. In the late 1800s, the first steps were taken toward self-government in British India with the appointment of Indian councilors to advise the British viceroy and the establishment of provincial councils with Indian members; the British subsequently widened participation in legislative councils. Beginning in 1920, Indian leader Mohandas K. Gandhi transformed the Indian National Congress political party into a mass movement to campaign against British colonial rule. The party used both parliamentary and nonviolent resistance and non-cooperation to achieve independence.
On August 15, 1947, India became a dominion within the Commonwealth, with Jawaharlal Nehru as Prime Minister. Enmity between Hindus and Muslims led the British to partition British India, creating East and West Pakistan, where there were Muslim majorities. India became a republic within the Commonwealth after promulgating its constitution on January 26, 1950.