The Partition of India in 1947 involved the largest mass migration in history as the British partitioned their Indian empire along religious lines into the secular states of India and Pakistan. An estimated 12-15 million people were displaced as Hindus and Sikhs migrated to India while Muslims moved to Pakistan. The poorly planned partition led to widespread violence and up to 1 million deaths as religious communities attacked each other. Long-term effects included population displacement, state border disputes like in Kashmir, and separation of families across the new borders.