Such modern cities as Breslau and Smyrna have suffered widespread destruction and demographic transformation in the wake of armed invasion. The neighbouring Punjabi cities of Lahore and Amritsar shared this experience, at the time of the 1947 division of the Indian subcontinent. Almost 40 per cent of Amritsar's houses were destroyed or damaged and its Muslim population fell from 49 per cent of the population on the eve of partition to just 00.52 per cent in 1951. Six thousand houses were damaged in Lahore and its Hindu and Sikh population who formed over a third of the population departed for India. The Luftwaffe had destroyed some 4185 houses in Coventry in an air raid for ever associated with the concept of concentrated bombing. The greater damage in peacetime Lahore and Amritsar was a result of disturbances surrounding the end of British rule. The cities lay at the heart of the region which bore the brunt of the 1947 upheaval. Ten million Punjabis were uprooted. In all around 13 million people were displaced by partition. This was the largest migration in a century whose wars and ethnic conflicts rendered millions of people homeless. The cities' proximity to the border (see map.) meant that they received large numbers of refugees. There were a million in Lahore alone in April 1948, two fifths of whom were housed in camps.