The fertile land of the five rivers (punj+ab in Persian) has persistently stirred the imagination of its peoples. Its story is the story of invasion. In 326 BCE Alexander the Great marched through the Hindu Kush, conquered the verdant plains now divided between India and Pakistan, and stamped Greek cultural and linguistic influence on the region. Over the centuries the lure of the Punjab attracted further waves of outsiders: Scythians, Sassanians,...