Immediately following independence in 1947, and due to the ensuing communal violence and fear, most Sikhs and Punjabi Hindus who found themselves in Pakistan migrated to India. Following independence, several small Punjabi princely states, including Patiala, acceded to the Union of India and were united into the PEPSU. In 1956 this was integrated with the state of East Punjab to create a new, enlarged Indian state called simply "Punjab". "Punjab Day" is celebrated across the state on 1 November every year marking the formation of a Punjabi language speaking state under the Punjab Reorganisation Act (1966). From 1981 to 1995 the state suffered a 14-year long insurgency which culminated with Operation Blue Star, and the assassination of India's Prime Minister.