 Centred around cities such as Mohenjo-daro, Harappa, Dholavira, and Kalibangan, and relying on varied forms of subsistence, the civilisation engaged robustly in crafts production and wide-ranging trade.During the period 2000–500 BCE, many regions of the subcontinent transitioned from the Chalcolithic cultures to the Iron Age ones.The Vedas, the oldest scriptures associated with Hinduism, were composed during this period, and historians have analysed these to posit a Vedic culture in the Punjab region and the upper Gangetic Plain.