The division of British India in August 1947 into the independent states of India and Pakistan — accompanied by the largest mass migration in human history, between one and two million deaths, and the displacement of fifteen million people — that shaped the subcontinent's politics for generations.
The British left India in six weeks. They drew a line through Punjab and Bengal — two of the most densely populated regions on earth — without surveying the ground or consulting the people who lived there. What followed was one of the bloodiest episodes of the twentieth century. The line is still there.