In 1600, the British East India Company was established, and in 1858, The India Act allowed for power to be transferred to the British government. The British Government never had complete control, but it certainly had power.
The Partition of India happened on August 14th, 1947 and August 15th, 1947. When the British left India on August 15th, 1947 (after the formation of the Islamic Republic of Pakistan), they left the country divided. This led to the formation of Pakistan and India, and later, in 1971, Bangladesh declared its independence from Pakistan.
When the British had occupied India, they categorized the people of India by religion, and treated them as separate groups.
A Hindu revival happened around the time of the Partition. They still had bitterness towards Muslims (who had been the predominant rulers of India before the British). They tried to band the slaughter of cows, change the national language to Hindi, and change the Devanagri script to Hindi.
Although the Sikhs (who originated in Punjab) were a minority in the population of India, they were conflicted with the Muslims, and were forced to leave Punjab and migrate to Hindu India. (They were not conflicted with Hindus).
The All India Muslim League (AIML) started in 1906 with the goal to make Muslims equal in rights to Hindus. At the time, the Indian National Congress was made mostly of Hindus. In 1940, Jinnah (a leader equal to Ghandi, except that he represented Muslims, and Ghandi represented Hindus) stated at the Lahore Conference that promoted a Muslim nation separate from the rest of India. In 1943, the AIML called for Britain to Divide and Quit. Hindus also acknowledged the difference in beliefs that separated them from Muslims. Between 1940 and 1942, Congress began plans to remove the British (the National Congress was calling for Britain to Quit India).
Due to the conflicting ideas on the separate sides, the...