How did the 1947 partition divide Bengal between India and Pakistan?

The 1947 partition of Bengal was a pivotal event that accompanied the end of British colonial rule and the creation of the independent dominions of India and Pakistan. The division was formalized by the Radcliffe Line, an international boundary established by a commission chaired by British lawyer Cyril Radcliffe.123

The partition split the region along communal lines:
* West Bengal: The western sector, which had a Hindu majority, became a state within the new dominion of India.12
* East Bengal: The eastern sector, which was predominantly Muslim, became East Pakistan (later the independent nation of Bangladesh).12

This process was part of the broader partition of India, which triggered one of the largest and most tragic mass migrations in history, marked by widespread communal violence. Following the partition, West Bengal faced the immense administrative challenge of rehabilitating more than seven million refugees who fled from East Pakistan.32