When India became independent on August 15, 1947, the Muslim Nizam refused to accede to the Indian Union (although it entirely surrounded his territory), demanding the right as ruler of 18 million (overwhelmingly Hindu) subjects to rule a separate state.
The resulting standoff ended with the state's occupation by Indian troops on September 13-17, 1948 and its subsequent incorporation as a state of India.
In November 1956 Hyderabad was divided along linguistic lines between the neighboring states of Andhra Pradesh to the east and south and Maharashtra to the west and north.