The Punjab is an ancient center of civilization. Historically it has been the main route of invasion and migration into India, going back beyond the Harappans. Harappa itself is on the Ravi in Punjab near present-day Montgomery, while Mohenjo Daro is on the Indus in Sindh just outside the natural gateway to Punjab that is formed as the Suliman range curves southward to squeeze the five rivers together. Remains of Numerous Harappan communities extend from there to Gujarat in the west and to the upper Jamuna in the east. Invaders since the Harappans have included the ancient Aryans who are responsible for the Rig Veda, Scythians, Greeks (Alexander the Great came as far as the Ravi), Arabs, Persians, Afghans, Pathans, Baluchis, Mongols, and Europeans. Each group has left its marks.
The chief historic cities of Punjab are Lahore, Amritsar, Ludhiana, Jalandhar, and Patiala. They are part of a line of commercial and military centers that lie along ancient routes from the Khyber Pass through the Ganges Plain. Along this route, rainfall is reliable, soils are deep, groundwater is accessible, and the climate is moderate. Cities in this belt south and east of Punjab include Delhi, Varanasi, Lucknow, Meerut, Allahabad, and Patna. These linkages keep Punjab in constant communication with surrounding regions. Punjabi culture has never been isolated.
Modern Punjabi culture has been shaped profoundly by the partitioning of India and Pakistan that accompanied independence in 1947. This event resulted in massive migrations that separated Muslims from Hindus and Sikhs, drove the Sikh cultivators who had been the backbone of the canal colonies to India, made Sikhs for the first time an actual majority in rural areas of central Indian Punjab, and initiated Divergent government policies that have had far-reaching effects on all areas of life.