Pre partition India mainly consisted of British controlled areas and sovereign princely states which were not fully and formally part of British India.
In a call for independence from British Rule, Cyril Radcliffe, who had never been to India was given less than 40 days to draw up the new borders based on outdated maps and census data.
The Muslim League advocated for a separate Muslim-majority nation-state. While Radcliffe’s borders however kept their political base in India, instead of including it within Pakistan’s borders. And his borders also left most economic centres like Delhi, Bombay and Calcutta within India, leaving the future Pakistan at an economic disadvantage. To make matters worse, the British unexpectedly moved the date of their exit up by ten months.
It also meant cutting two of India’s most powerful and populous provinces in half; Punjab and Bengal, home to Muslims, Hindus & Sikhs alike. Fearing religious persecution, many Muslims fled to Pakistan, while Hindus and Sikhs moved across the border to India. But many never made it to their destinations. It marked the origins of India and Pakistan, with horrific bloodshed. The partition of India led to violent riots and mass migration along the newly created borders.
Two new countries were born, India and Pakistan. The largely Muslim state was comprised of East and West Pakistan, separated by more than 1,500 km of Indian territory.
Most princely states accede to either India or Pakistan, while a few others remain independent. Another province, Kashmir, a largely Muslim territory which fell on the border, became the centre of a different conflict. With a dispute over ownership, Pakistan and India go to war over Kashmir which ends with the creation of a cease fire line.
Almost immediately after partition, the Bengalis were subject to ethnic oppression by their new Pakistani rulers. Bengali culture was forced to submit to that of West Pakistan and there was a large effort to replace the Bengali language with Urdu. After years of Bengali calls for independence, West Pakistan began what is by many considered a genocide of the Bengali people.
The Awami League, a Bengali nationalist party, lead by Sheikh Mujibur won a landslide victory in the 1970 elections by an absolute majority of 160 seats. The Assembly was initially not inaugurated as President Yahya Khan and the Pakistan Peoples Party did not want a party from East Pakistan in government. This caused great unrest in East Pakistan which soon escalated into the call for independence on March 26, 1971 and ultimately sparked the 1971 Bangladesh Liberation War. Pakistan’s military junta enacted “Operation Searchlight”, in which soldiers rounded up and executed those of Bengali ethnicity, regardless of their religious affiliation.
For 9 months, the Pakistani military killed between half a million and three million Bengali people, and raped as many as 400,000 women. When Pakistan began bombing portions of Northern India in their campaign, India then entered the war against Pakistan. East Pakistan finally became the independent state of Bangladesh a month later. To this day, Pakistan has refused to acknowledge what has been called the Bengali genocide, and the overall number of casualties.
India and Pakistan again go to war over Kashmir with a Line of control established. Kashmir remains a disputed territory till this day.