After the decline of the Indus Civilization numerous cultures developed across north India. Copper, followed by iron, came to be widely used. Iron helped to expand areas of cultivation leading to agrarian surplus. As this facilitated feeding of more number of people there were greater instances of in-migration and population growth. The Late Harappan cultures suggest that some of the groups moved into eastern direction, after the decline of the Indus Civilization.
The Chalcolithic culture, including the OCP cultures, flourished in different parts of India. People belonging to these cultures began to engage in pastoral as well as agricultural activities.
The Aryans migrated to India around 1500 BCE. The Vedic texts form an important source of this period. Horses and iron are associated with the Aryans.
The Rig Veda, the earliest text in Sanskrit, portrays the society and culture of the early Vedic period. The early Vedic culture was characterized by pastoral as well as agricultural practices. People worshiped nature in the form of deities such as Agni, Varuna and Surya.
The Later Vedic period for which Yajur, Sama and Atharva Vedas are the source, evolved into a complex and rigid society. The four-fold division of the society, namely, Brahamana, Kshtatriya, Vaishya and Sudra, became well established in this period. Social groups of the Later Vedic societies were organised into chiefdoms.