Indo-Aryan Migration and the Early Vedic Period Begins

The event

In the centuries following the decline of the old Indus cities, pastoral, cattle-herding, chariot-driving peoples speaking an early form of Sanskrit settled the Punjab and gradually pushed east into the Ganges plain. Their society organized around clans and, over time, a hardening division of labor that would eventually become the caste system, while worship centered on fire sacrifice offered to a pantheon of nature-deities — Indra the storm-warrior, Agni the fire-god, and Varuna, guardian of cosmic order, chief among them.

Sanskrit belongs to the same Indo-European language family as Greek, Latin, Persian, and eventually English, and its arrival in India is part of a much wider set of Indo-European migrations spreading across Eurasia in this same era — a vivid, if secular, illustration of the scattering and multiplying of Noah's descendants across the earth that Genesis 10–11 describes in its own terms.

This period runs roughly alongside Israel's exodus from Egypt and conquest of Canaan under Joshua. While Israel was being formed as a people who would know and worship the one true God by His own revelation, other peoples across the earth were fashioning elaborate worship of nature and its forces — not because they had no knowledge of God at all (Romans 1:19–20; 2:14–15), but because fallen humanity everywhere suppresses what can be known of Him and exchanges it for substitutes of its own making (Romans 1:21–23).

Dating

Mainstream historical linguistics holds that Indo-Aryan-speaking peoples migrated into the Indus-Ganges plains from Central Asia in overlapping waves from around 1500 BC, based on Sanskrit's close kinship to Persian, Greek, and Latin. Some Hindu traditionalist scholars instead argue for an 'Out of India' model in which Vedic culture originated within India and spread outward, dating Vedic civilization much earlier. This remains a genuinely and sometimes sharply contested question; the migration model remains the position of most secular historical linguists.