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The Indo-Aryan migrations were the migrations into the Indian subcontinent of Indo-Aryan peoples, an ethnolinguistic group that spoke Indo-Aryan languages, the predominant languages of today's North India, Pakistan, Nepal, Bangladesh, Sri Lanka and the Maldives. Indo-Aryan population movements into the region and Anatolia (ancient Mitanni) from Central Asia are considered to have started after 2000 BCE, as a slow diffusion during the Late Harappan period, which led to a language shift in the northern Indian subcontinent. The Iranian languages were brought into the Iranian plateau by the Iranians, who were closely related to the Indo-Aryans.

The Proto-Indo-Iranian culture, which gave rise to the Indo-Aryans and Iranians, developed on the Central Asian steppes north of the Caspian Sea as the Sintashta culture (2200–1800 BCE) in present-day Russia and Kazakhstan, and developed further as the Andronovo culture (2000–900 BCE), around the Aral Sea.

The Indo-Aryans split off around 2000 BCE to 1600 BCE from the Iranians, and migrated southwards to the Bactria–Margiana Culture (BMAC), from which they borrowed their distinctive religious beliefs and practices. From the BMAC, the Indo-Aryans migrated into Anatolia and, possibly in multiple waves, the Punjab (northern Pakistan and India), while the Iranians, starting c. 800 BCE, moved into Iran, both bringing with them the Indo-Iranian languages.

Migration by an Indo-European people was first hypothesized in the late 18th century, following the discovery of the Indo-European language family, when similarities between western and Indian languages had been noted. Given these similarities, a single source or origin was proposed, which was diffused by migrations from some original homeland.

This linguistic argument is supported by archaeological, anthropological, genetic, literary and ecological research. Genetic research reveals that those migrations form part of a complex genetic puzzle on the origin and spread of the various components of the Indian population. Literary research reveals similarities between various, geographically distinct, Indo-Aryan historical cultures. Ecological studies reveal that in the second millennium BCE widespread aridization lead to water shortages and ecological changes in both the Eurasian steppes and the Indian subcontinent, causing the collapse of sedentary urban cultures in south central Asia, Afghanistan, Iran, and India, and triggering large-scale migrations, resulting in the merger of migrating peoples with the post-urban cultures.

The Indo-Aryan migrations started in approximately 2000 BCE, after the invention of the war chariot, and also brought Indo-Aryan languages into the Levant and possibly Inner Asia. It was part of the diffusion of Indo-European languages from the proto-Indo-European homeland at the Pontic–Caspian steppe, a large area of grasslands in far Eastern Europe, which started in the 5th to 4th millennia BCE, and the Indo-European migrations out of the Eurasian Steppes, which started approximately in 2000 BCE.

These Indo-Aryan speaking people were united by shared cultural norms and language, referred to as ārya, "noble". Diffusion of this culture and language took place by patron-client systems, which allowed for the absorption and acculturation of other groups into this culture, and explains the strong influence on other cultures with which it interacted.