Oral literature datable after 1000 BC shows that the geographical focus of the Indo-Aryans had moved by now from the northern portion of the Ganges Valley to its centre, the region regarded later as the heartland of traditional Hindu culture.
Although the literature speaks only of the Aryans, the colonists were undoubtedly ethnically mixed. The regions they were entering were heavily wooded and forest clearance by sacrificial fire is mentioned in the texts. Iron tools, coming into use in the 1st millennium BC, were also of great utility in clearing and preparing land.
Rice and other cereals were grown and domestic animals raised by peasants, many of whom were probably of indigenous stock, while the warrior aristocracy continued their raiding and warfare.
The aggressive attitude of these tribes to their neighbours is typified by the traditional horse sacrifice, asvamedha. A horse destined for sacrifice was allowed to wander free for a year, followed by royal soldiers ready to lay claim by military force to all the lands it entered. This remained a traditional means to assert authority over a wide territory well into historical times.
The legendary Battle of the Ten Kings was fought out between confederacies of tribes: this reflects co-operation between groups and the development of larger political entities, a phenomenon that characterized the later history of Middle India.
Some villages were beginning to grow into towns; many of these have been excavated but attempts to discover concrete evidence of legendary events have been disappointed. Most towns have relatively insubstantial remains before about 500 BC, traces of wattle and daub houses usually accompanied by characteristic Painted Grey Ware pottery.
Similar remains in areas of Central India beyond the Ganges region show the progressive outward expansion of these tribes.
