Eastern South Asia region is bounded by Nepal, Sikkim, and Bhutan in the north, Bangladesh in the east, the Indian states of Uttar Pradesh and Chhattisgarh on the west, and the Indian state of Andhra Pradesh in the south. It is connected to the Seven Sister States of Northeast India by the narrow Siliguri Corridor. West Bengal is on the eastern bottleneck of India, stretching from the Himalayas in the north, to the Bay of Bengal in the south. The region lies in the humid-subtropical zone. The landlocked region of Northeast India includes the states of Assam, Arunachal Pradesh, Bihar, Mizoram, Manipur, Meghalaya,
Eastern South Asia India. East Bengal was later renamed East Pakistan in 1955. In 1971, East Pakistan seceded in the Bangladesh Liberation War, which established the People's Republic of Bangladesh. The constitution of Bangladesh established a multiparty parliamentary democracy in 1972. The country endured several military coups in the late 1970s and 1980s. Islam is the state religion of Bangladesh. In the Indian state of West Bengal, the Communist Party of India governed for three decades. The Eastern Himalayas has been home to three independent kingdoms since the 17thcentury, including the Kingdom of Bhutan, the Kingdom of Sikkim, and the Kingdom of Nepal.