For millennia it has been worshipped as a god; for centuries used as a tool of imperial expansion; today it is the cement of Pakistans fractious union. Five thousand years ago, a string of sophisticated cities grew and traded on its banks. In the ruins of these elaborate metropolises, Sanskrit-speaking nomads explored the river, extolling its virtues in Indias most ancient text, the Rig-Veda. During the past two thousand years a series of invaders Alexander the Great, Afghan Sultans, the British Raj made conquering the Indus valley their quixotic mission. For the people of the river, meanwhile, the Indus valley became a nodal point on the Silk Road, a centre of Sufi pilgrimage and the birthplace of Sikhism. Empires of the Indus follows the river upstream and back in time, taking the reader on a voyage through two thousand miles of geography and more than five millennia of history redolent with contemporary importance.