The Indo-Aryan peoples (or Indic peoples) are a diverse collection of ethnolinguistic groups speaking Indo-Aryan languages, a subgroup of the Indo-European language family. Indo-Aryan peoples are native to the northern Indian subcontinent, and presently found all across South Asia, where they form the majority.[note 1]
The Indo-Aryan migration theory,[note 2] proposed among others by anthropologist David W. Anthony (in The Horse, The Wheel and Language) and by archaeologists Elena Efimovna Kuzmina and J. P. Mallory, shows that the introduction of the Indo-Aryan languages in the Indian subcontinent was the result of a migration of people from the Sintashta culture through the Bactria-Margiana Culture and into the northern Indian subcontinent (modern-day India, Nepal, Bangladesh, Pakistan and Sri Lanka). These migrations started approximately 1,800 BCE, after the invention of the war chariot, and also brought Indo-Aryan languages into the Levant and possibly Inner Asia and western China. The Proto-Indo-Iranians, from which the Indo-Aryans developed, are identified with the Sintashta culture (2100–1800 BCE), and the Andronovo culture, which flourished ca. 1800–1400 BCE in the steppes around the Aral sea, present-day Kazakhstan, Uzbekistan and Turkmenistan. The proto-Indo-Iranians were influenced by the Bactria-Margiana Culture, south of the Andronovo culture, from which they borrowed their distinctive religious beliefs and practices. The Indo-Aryans split off around 1800–1600 BCE from the Iranians, whereafter the Indo-Aryans migrated into the Levant and north-western India. This migration was part of the diffusion of Indo-European languages from the Proto-Indo-European homeland at the Pontic steppe which started in the 4th millennia BCE.
The Indo-Aryans were united by shared cultural norms and language, referred to as aryā, "noble." Diffusion of this culture and language took place by patron-client systems, which allowed for the absorption and acculturalisation of other groups into this culture, and explains the strong influence on other cultures with which it interacted.
The alternate Indigenous Aryans theory places the Indo-Aryans languages as being entirely indigenous to the Indian subcontinent and later they spread outside the subcontinent; this theory has no support in mainstream scholarship.