The two-nation theory was an ideology of religious nationalism that advocated Muslim Indian nationhood, with separate homelands for Indian Muslims and Indian Hindus within a decolonised British India, which ultimately led to the Partition of India in 1947. Its various descriptions of religious differences were the main factor in Muslim separatist thought in the Indian subcontinent, asserting that Indian Muslims and Indian Hindus are two separate nations, each with their own customs, traditions, art, architecture, literature, interests, and ways of life.

The Partition of India in 1947 was the change of political borders and the division of other assets that accompanied the dissolution of the British Raj in the Indian subcontinent and the creation of two independent dominions in South Asia: India and Pakistan. The Dominion of India is today the Republic of India, and the Dominion of Pakistan—which at the time comprised two regions lying on either side of India—is now the Islamic Republic of Pakistan and the People's Republic of Bangladesh. The partition was outlined in the Indian Independence Act 1947. The change of political borders notably included the division of two provinces of British India, Bengal and Punjab. The majority Muslim districts in these provinces were awarded to Pakistan and the majority non-Muslim to India. The other assets that were divided included the British Indian Army, the Royal Indian Navy, the Royal Indian Air Force, the Indian Civil Service, the railways, and the central treasury. Provisions for self-governing independent Pakistan and India legally came into existence at midnight on 14 and 15 August 1947 respectively.