# Indo-Iranians

The Indo-Iranian peoples, also known as Ā́rya or Aryans from their self-designation, were a group of Indo-European speaking peoples who brought the Indo-Iranian languages to parts of Europe, Central Asia, and South Asia in waves from the first part of the 2nd millennium BC onwards. They eventually branched out into the Iranian peoples and Indo-Aryan peoples.

## Nomenclature

The term Aryan has long been used to denote the Indo-Iranians, because Ā́rya was the self-designation of the ancient speakers of the Indo-Iranian languages, specifically the Iranian and the Indo-Aryan peoples, collectively known as the Indo-Iranians. Despite this, some scholars use the term Indo-Iranian to refer to this group, though the term "Aryan" remains widely used by most scholars, such as Josef Wiesehofer, Will Durant, and Jaakko Häkkinen. Population geneticist Luigi Luca Cavalli-Sforza, in his 1994 book The History and Geography of Human Genes, also uses the term Aryan to describe the Indo-Iranians.

## History
### Origin

The Proto-Indo-Iranians are commonly identified with the descendants of the Indo-Europeans known as the Sintashta culture and the subsequent Andronovo culture within the broader Andronovo horizon, and their homeland with an area of the Eurasian steppe that borders the Ural River on the west, the Tian Shan on the east (where the Indo-Iranians took over the area occupied by the earlier Afanasevo culture), and Transoxiana and the Hindu Kush on the south.
Based on its use by Indo-Aryans in Mitanni and Vedic India, its prior absence in the Near East and Harappan India, and its 19th–20th century BC attestation at the Andronovo site of Sintashta, Kuzmina (1994) argues that the chariot corroborates the identification of Andronovo as Indo-Iranian. Anthony & Vinogradov (1995) dated a chariot burial at Krivoye Lake to about 2000 BC, and a Bactria-Margiana burial that also contains a foal has recently been found, indicating further links with the steppes.
Historical linguists broadly estimate that a continuum of Indo-Iranian languages probably began to diverge by 2000 BC,$^{:38–39}$ preceding both the Vedic and Iranian cultures which emerged later. The earliest recorded forms of these languages, Vedic Sanskrit and Gathic Avestan, are remarkably similar, descended from the common Proto-Indo-Iranian language. The origin and earliest relationship between the Nuristani languages and that of the Iranian and Indo-Aryan groups is not completely clear.

### Expansion
#### First wave – Indo-Aryans

Two-wave models of Indo-Iranian expansion have been proposed by Burrow (1973) and Parpola (1999). The Indo-Iranians and their expansion are strongly associated with the Proto-Indo-European invention of the chariot. It is assumed that this expansion spread from the Proto-Indo-European homeland north of the Caspian Sea south to the Caucasus, Central Asia, the Iranian plateau, and the Indian subcontinent.

##### The Mitanni of Anatolia

The Mitanni, a people known in eastern Anatolia from about 1500 BC, were of possibly of mixed origins: An indigenous non Indo-European Hurrian-speaking majority was supposedly dominated by a non-Anatolian, Indo-Aryan elite.$^{:257}$ There is linguistic evidence for such a superstrate, in the form of:
* a horse training manual written by a Mitanni man named Kikkuli, which was translated into the Hittite language
* the names of Mitanni rulers and;
* the names of gods invoked by these rulers in treaties.
In particular, Kikkuli's text includes words such as aika "one" (i.e. a cognate of the Indo-Aryan eka), tera "three" (tri), panza "five" (pancha), satta "seven", (sapta), na "nine" (nava), and vartana "turn around", in the context of a horse race (Indo-Aryan vartana). In a treaty between the Hittites and the Mitanni, the Ashvin deities Mitra, Varuna, Indra, and Nasatya are invoked. These loanwords tend to connect the Mitanni superstrate to Indo-Aryan rather than Iranian languages – i.e. the early Iranian word for "one" was aiva.

##### Indian subcontinent – Vedic culture

The standard model for the entry of the Indo-European languages into the Indian subcontinent is that this first wave went over the Hindu Kush, either into the headwaters of the Indus and later the Ganges. The earliest stratum of Vedic Sanskrit, preserved only in the Rigveda, is assigned to roughly 1500 BC.$^{:258}$ From the Indus, the Indo-Aryan languages spread from c. 1500 BC – c. 500 BC, over the northern and central parts of the subcontinent, sparing the extreme south. The Indo-Aryans in these areas established several powerful kingdoms and principalities in the region, from south eastern Afghanistan to the doorstep of Bengal. The most powerful of these kingdoms were the post-Rigvedic Kuru (in Kurukshetra and the Delhi area) and their allies the Pañcālas further east, as well as Gandhara and later on, about the time of the Buddha, the kingdom of Kosala and the quickly expanding realm of Magadha. The latter lasted until the 4th century BC, when it was conquered by Chandragupta Maurya and formed the center of the Maurya Empire.
In eastern Afghanistan and some western regions of Pakistan, Indo-Aryan languages were eventually replaced by Eastern Iranian languages. Most Indo-Aryan languages, however, were and still are prominent in the rest of the Indian subcontinent. Today, Indo-Aryan languages are spoken in India, Pakistan, Bangladesh, Nepal, Sri Lanka, Fiji, Suriname and the Maldives.

#### Second wave – Iranians

The second wave is interpreted as the Iranian wave.$^{:42–43}$
The first Iranians to reach the Black Sea 'may' have been the Cimmerians in the 8th century BC, although their linguistic affiliation to Iranians is uncertain. They were followed by the Scythians, who are considered a western branch of the Central Asian Sakas. Sarmatian tribes, of whom the best known are the Roxolani (Rhoxolani), Iazyges (Jazyges) and the Alani (Alans), followed the Scythians westwards into Europe in the late centuries BC and the 1st and 2nd centuries AD (The Age of Migrations). The populous Sarmatian tribe of the Massagetae, dwelling near the Caspian Sea, were known to the early rulers of Persia in the Achaemenid Period. At their greatest reported extent, around 1st century AD, the Sarmatian tribes ranged from the Vistula River to the mouth of the Danube and eastward to the Volga, bordering the shores of the Black and Caspian seas as well as the Caucasus to the south. In the east, the Saka occupied several areas in Xinjiang, from Khotan to Tumshuq.
The Medians, Persians and Parthians begin to appear on the Iranian plateau from c. 800 BC, and the Achaemenids replaced the language isolate speaking Elamites rule over the region from 559 BC, although the Iranic peoples were largely subject to the Semitic speaking Assyrian Empire until the 6th century BC. Around the first millennium AD, Iranian groups began to settle on the eastern edge of the Iranian plateau, on the mountainous frontier of northwestern and western Indian subcontinent, displacing the earlier Indo-Aryans from the area.
In Eastern Europe, the Iranians were eventually decisively assimilated (e.g. Slavicisation) and absorbed by the Proto-Slavic population of the region, while in Central Asia, the Turkic languages marginalized the Iranian languages as a result of the Turkic expansion of the early centuries AD. Extant major Iranian languages are Persian, Pashto, Kurdish, and Balochi besides numerous smaller ones. Ossetian, primarily spoken in North Ossetia and South Ossetia, is a direct descendant of Alanic, and by that the only surviving Sarmatian language of the once wide-ranging East Iranian dialect continuum that stretched from Eastern Europe to the eastern parts of Central Asia.

## Archaeology

Archaeological cultures associated with Indo-Iranian expansion include:
* Europe
** Poltavka culture (2500–2100 BC)
** Abashevo culture (2300–1850 BC)
** Srubna culture (1850–1450 BC)
* Central Asia
** Sintashta-Petrovka-Arkaim (2050–1750 BC)
** Andronovo horizon (2000–1450 BC)
*** Alakul (2100–1400 BC)
*** Fedorovo (1400–1200 BC)
*** Alekseyevka (1200–1000 BC)
** Bactria-Margiana Archaeological Complex (2200–1700 BC)
** Yaz culture (1500–1100 BC)
* Indian subcontinent
** Ochre Coloured Pottery culture (2000–1500 BC)
** Cemetery H culture (1900–1300 BC)
** Swat culture (1400–800 BC)
** Painted Gray Ware culture (1200–600 BC)
* Iranian Plateau
** Early West Iranian Grey Ware (1500–1000 BC)
** Late West Iranian Buff Ware (900–700 BC)
Parpola (1999) suggests the following identifications:
| Date range | Archaeological culture | Identification suggested by Parpola |
| 2800–2000 BC | late Catacomb and Poltavka cultures | late PIE to Proto–Indo-Iranian |
| 2000–1800 BC | Srubna and Abashevo cultures | Proto-Iranian |
| 2000–1800 BC | Petrovka-Sintashta | Proto–Indo-Aryan |
| 1900–1700 BC | BMAC | "Proto-Dasa" Indo-Aryans establishing themselves in the existing BMAC settlements, defeated by "Proto-Rigvedic" Indo-Aryans around 1700 |
| 1900–1400 BC | Cemetery H | Indian Dasa |
| 1800–1000 BC | Alakul-Fedorovo | Indo-Aryan, including "Proto–Sauma-Aryan" practicing the Soma cult |
| 1700–1400 BC | early Swat culture | Proto-Rigvedic |
| 1700–1500 BC | late BMAC | "Proto–Sauma-Dasa", assimilation of Proto-Dasa and Proto–Sauma-Aryan |
| 1500–1000 BC | Early West Iranian Grey Ware | Mitanni-Aryan (offshoot of "Proto–Sauma-Dasa") |
| 1400–800 BC | late Swat culture and Punjab, Painted Grey Ware | late Rigvedic |
| 1400–1100 BC | Yaz II-III, Seistan | Proto-Avestan |
| 1100–1000 BC | Gurgan Buff Ware, Late West Iranian Buff Ware | Proto-Persian, Proto-Median |
| 1000–400 BC | Iron Age cultures of Xinjiang | Proto-Saka |

## Language

The Indo-European language spoken by the Proto-Indo-Iranians in the late 3rd millennium BC was a Satem language still not removed very far from the Proto-Indo-European language, and in turn only removed by a few centuries from Vedic Sanskrit of the Rigveda. The main phonological change separating Proto-Indo-Iranian from Proto–Indo-European is the collapse of the ablauting vowels *e, *o, *a into a single vowel, Proto–Indo-Iranian *a (but see Brugmann's law). Grassmann's law and Bartholomae's law were also complete in Proto-Indo-Iranian, as well as the loss of the labiovelars (kw, etc.) to k, and the Eastern Indo-European (Satem) shift from palatized k' to ć, as in Proto–Indo-European *k'ṃto- > Indo-Iran. *ćata- > Sanskrit śata-, Old Iran. sata "100".
Among the sound changes from Proto-Indo-Iranian to Indo-Aryan is the loss of the voiced sibilant *z, among those to Iranian is the de-aspiration of the PIE voiced aspirates.
The regions where Indo-Iranian languages are spoken extend from Europe (Romani) and the Caucasus (Ossetian, Tat and Talysh), down to Mesopotamia (Kurdish languages, Zaza–Gorani and Kurmanji Dialect continuum) and Iran (Persian), eastward to Xinjiang (Sarikoli) and Assam (Assamese), and south to Sri Lanka (Sinhala) and the Maldives (Maldivian), with branches stretching as far out as Oceania and the Caribbean for Fiji Hindi and Caribbean Hindustani respectively. Furthermore, there are large diaspora communities of Indo-Iranian speakers in northwestern Europe (the United Kingdom), North America (United States, Canada), Australia, South Africa, and the Persian Gulf Region (United Arab Emirates, Saudi Arabia).

## Religion

Proto-Indo-Iranian religion is an archaic offshoot of Indo-European religion. From the various and dispersed Indo-Iranian cultures, a set of common ideas may be reconstructed from which a common, unattested proto-Indo-Iranian source may be deduced.
Indo-Iranians shared a common inheritance of concepts including the universal force *Hṛta- (Sanskrit rta, Avestan asha), the sacred plant and drink *sawHma- (Sanskrit Soma, Avestan Haoma) and gods of social order such as *mitra- (Sanskrit Mitra, Avestan and Old Persian Mithra, Miθra) and *bʰaga- (Sanskrit Bhaga, Avestan and Old Persian Baga). The Rig-Vedic Sarasvati is linguistically and functionally cognate with Avestan *Haraxvaitī Ārəduuī Sūrā Anāhitā. Both are described as world rivers. Vedic Saraswati is described as "Best of Mothers, Best of Rivers, Best of Goddesses". Similarly, in early portions of the Avesta, Iranian *Harahvati is the world-river that flows down from the mythical central Mount Hara. She is blocked by an obstacle (Avestan for obstacle: vərəθra) placed there by Angra Mainyu.

## Genetics

R1a1a (R-M17 or R-M198) is the sub-clade most commonly associated with Indo-European populations. Most discussions purportedly of R1a origins are actually about the origins of the dominant R1a1a (R-M17 or R-M198) sub-clade. R1a1a is found in two major variations: Z93 and Z282. R-Z93 appears to encompass most of the R1a1a found in Asia, being related to Indo-Iranians. On the other hand, R-Z282 is the main European branch of R1a1a predominantly related to Balts and Slavs in Eastern Europe. Data so far collected indicates high frequency of R-Z93 in the northern Indian Subcontinent, Tajikistan, and Afghanistan: Bengali Brahmins carry up to 72% R1a1a, Mohana tribe up to 71%, Nepal Hindus up to 69.20%, and Tajiks up to 68%. In the western part of Iran, Iranians show low R1a1a levels, while males of eastern parts of Iran carry up to 35% R1a1a. The historical and prehistoric possible reasons for this are the subject of on-going discussion and attention amongst population geneticists and genetic genealogists, and are considered to be of potential interest to linguists and archaeologists also.
Out of 10 human male remains assigned to the Andronovo horizon from the Krasnoyarsk region, 9 possessed the R1a Y-chromosome haplogroup and one C-M130 haplogroup (xC3). mtDNA haplogroups of nine individuals assigned to the same Andronovo horizon and region were as follows: U4 (2 individuals), U2e, U5a1, Z, T1, T4, H, and K2b.
A 2004 study also established that during the Bronze Age/Iron Age period, the majority of the population of Kazakhstan (part of the Andronovo culture during the Bronze Age), was of west Eurasian maternal lineages (with mtDNA haplogroups such as U, H, HV, T, I and W), and that prior to the 13th–7th century BC, all Kazakh samples belonged to European lineages.
A 2022 study found that modern individuals from Southern Central Asia, especially Tajiks and Yaghnobis, display strong genetic continuity towards Iron Age Indo-Iranians, and were only marginally affected by outside geneflow, while modern Turkic peoples derive significant amounts of ancestry from a 'Baikal hunter-gatherer' source (mean average ~50%), with the remainder being ancestry maximized in Tajik people. Historical Indo-Iranians showed high genetic affinity towards European hunter-gatherers and Iranian Neolithic farmers.