Synopsis The Heras Memorial Lectures honour the memory of an eminent historian and archaeologist, the Rev. Henry Heras, S.J., who came to India from Spain in 1922 to be Professor of Indian History at St. Xavier's College, Bombay. In 1926 he founded the Indian Historical Research Institute, later renamed the Heras Institute of Indian History and Culture. He died in Bombay in 1955, after spending more than half of his life in digging up India's past, in order to display to the world the glorious history and culture of the land he made his own and whose citizen he became. The present Lectures are the thirty-fifth in the Series. These lectures suggest alternatives to the 'holocaust' theories of civilizational collapse. They attempt to identify social, political, and religious processes that could account for the end of the Indus valley civilization, they argue for structural strains in Bronze Age systems. The Indus or Harappa civilization is placed in a wider geographic setting to explore not just internal factors but also those operating within the Bronze Age world at large. An appendix gives a brief survey of the post-Harappan cultures, for easy reference, for students. The text is illustrated with diagrams, maps and photographs.