Almost from the advent of independent Pakistan in 1947, frictions developed between East and West Pakistan, which were separated by more than 1,000 miles of Indian territory. East Pakistanis felt exploited by the West Pakistan-dominated central government. Linguistic, cultural, and ethnic differences also contributed to the [[estrangement]] of East from West Pakistan. Bengalis strongly resisted attempts to impose Urdu as the sole official language of Pakistan. Responding to these grievances, Sheikh Mujibur Rahman in 1948 formed a students' organization called the Chhatra League. In 1949, Maulana Abdul Hamid Khan Bhasani and some other Bengali leaders formed the East Pakistan Awami Muslim League (AL), a party designed mainly to promote Bengali interests. This party dropped the word Muslim from its name in 1955 and came to be known as Awami League. Mujib became president of the Awami League in 1966 and emerged as leader of the Bengali autonomy movement. In 1966, he was arrested for his political activities.
After the Awami League won almost all the East Pakistan seats of the Pakistan national assembly in 1970-71 elections, West Pakistan opened talks with the East on constitutional questions about the division of power between the central government and the provinces, as well as the formation of a national government headed by the Awami League. The talks proved unsuccessful, however, and on March 1, 1971, Pakistani President Yahya Khan indefinitely postponed the pending national assembly session, precipitating massive civil disobedience in East Pakistan. Mujib was arrested again; his party was banned, and most of his aides fled to India and organized a provisional government. On March 26, 1971, following a bloody crackdown by the Pakistan Army, Bengali nationalists declared an independent People's Republic of Bangladesh. As fighting grew between the army and the Bengali mukti bahini ("freedom fighters"), an estimated 10 million Bengalis, mainly Hindus, sought refuge in the Indian states of Assam and West Bengal. On April 17, 1971, a provisional government was formed in Meherpur district in western Bangladesh bordering India with Sheikh Mujibur Rahman, who was in prison in Pakistan, as Presidentpresident, Syed Nazrul Islam as Acting President, and Tajuddin Ahmed as Prime Minister.
The crisis in East Pakistan produced new strains in Pakistan's troubled relations with India. The two nations had fought a war in 1965, mainly in the west, but the refugee pressure in India in the fall of 1971 produced new tensions in the east. Indian sympathies lay with East Pakistan, and in November, India intervened on the side of the Bangladeshis. On December 16, 1971, Pakistani forces surrendered, and Bangladesh—meaning "Bengal country"—was born; the new country became a parliamentary democracy under a 1972 constitution.
The first government of the new nation of Bangladesh was formed in Dhaka with Justice Abu Sayeed Choudhury as Presidentpresident, and Sheikh Mujibur Rahman ("Mujib")--who was released from Pakistani prison in early 1972—as Prime Minister.
===Sheikh Mujibur Rahman, 1972-75===