The British partitioned these possessions into two states, India and Pakistan, with the Bengal region divided between the two. Pakistan’s land in Bengal, which was predominantly Muslim, was initially known as East Bengal, and then later as East Pakistan. Over 1000 miles separated the two parts of Pakistan as did differences in ethnicity, language and culture.
The frictions caused by these difference became evident after the first elections of the East Bengal Provincial Assembly in 1954. The ruling party of Pakistan, the Muslim League, won only nine seats whereas the United Front won 215 out of a possible 237. The United Front was an alliance of a number of political parties who shared the common goal of greater autonomy for East Pakistan.
The national government responded by dismissing the Provincial Assembly and installing a governor for a year, during which time the United Front failed to live up to its name: it divided into two factions. One of these factions, the secularist Awami League, won all the East Pakistan seats in the National Assembly during the 1970-71 elections putting them in position to possibly form a national government. The political negotiations between the Awami League and Pakistan Peoples Party, which had won a majority of the seats in West Pakistan broke down.
Faced with a political impasse and the break up of the nation, President Yahya Kahn indefinitely suspended the National Assembly resulting in massive civil disobedience in East Pakistan. Kahn responded to the revolt by sending in the Pakistan army to arrest the leader of the Awami League, Sheikh Mujibur Rahman, which precipitated a declaration of independence of Bangladesh by senior Bengali officers. The army’s ruthless suppression of the political agitation not only cost the lives of three million people in the eastern province, but also resulted in a civil war that eventually drew in India.
The combined forces of Bangladesh and India defeated the Pakistan army which surrendered in December 1971 paving the way for the establishment of a new state. On 11th January 1972, East Pakistan formally renamed itself Bangladesh with Sheikh Mujib Mujibur Rahman as head of state. A new constitution came into force in December of that year and the first elections were held the following March.