Ancient times
Vedic Sanskrit speakers viewed the term ā́rya as a religious–linguistic category, referring to those who spoke the Sanskrit language and adhered to Vedic cultural norms, especially those who worshipped the Vedic gods (Indra and Agni in particular), took part in the yajna and festivals, and practiced the art of poetry.
The 'non-Aryas' designated primarily those who were not able to speak the āryā language correctly, the Mleccha or Mṛdhravāc. However, āryā is used only once in the Vedas to designate the language of the texts, the Vedic area being defined in the Kauṣītaki Āraṇyaka as that where the āryā vāc ('Ārya speech') is spoken. Some 35 names of Vedic tribes, chiefs and poets mentioned in the Rigveda were of 'non-Aryan' origin, demonstrating that cultural assimilation to the ā́rya community was possible, and/or that some 'Aryan' families chose to give 'non-Aryan' names to their newborns. In the words of Indologist Michael Witzel, the term ārya "does not mean a particular people or even a particular 'racial' group but all those who had joined the tribes speaking Vedic Sanskrit and adhering to their cultural norms (such as ritual, poetry, etc.)".
In later Indian texts and Buddhist sources, ā́rya took the meaning of 'noble', such as in the terms Āryadésa- ('noble land') for India, Ārya-bhāṣā- ('noble language') for Sanskrit, or āryaka- ('honoured man'), which gave the Pali ayyaka- ('grandfather'). The term came to incorporate the idea of a high social status, but was also used as an honorific for the Brahmana or the Buddhist monks. Parallelly, the Mleccha acquired additional meanings that referred to people of lower castes or aliens.
In the words of scholar Gherardo Gnoli, the Old Iranian airya (Avestan) and ariya (Old Persian) were collective terms denoting the "peoples who were aware of belonging to the one ethnic stock, speaking a common language, and having a religious tradition that centred on the cult of Ahura Mazdā", in contrast to the 'non-Aryas', who are called anairya in Avestan, anaryān in Parthian, and anērān in Middle Persian.
The people of the Avesta, exclusively used the term airya (Avestan: 𐬀𐬌𐬭𐬌𐬌𐬀, airiia) to refer to themselves. It can be found in a number geographical terms like the 'expanse of the airyas' (airiianəm vaēǰō), the 'dwelling place of the airyas' (airiio.shaiianem), or the 'white forest of the airyas' (vīspe.aire.razuraya). The term can also be found in poetic expressions such as the 'glory of the airyas' (airiianąm xᵛarənō), the 'most swift-arrowed of the airyas' (xšviwi išvatəmō airiianąm), or the 'hero of the airyas' (arša airiianąm). Although the Avesta does not contain any dateable events, modern scholarship assumes that the Avestan period mostly predates the Achaemenid period of Iranian history.
By the late 6th–early 5th century BCE, the Achaemenid king Darius the Great and his son Xerxes I described themselves as ariya ('Arya') and ariya čiça ('of Aryan origin'). In the Behistun inscription, authored by Darius during his reign (522 – 486 BCE), the Old Persian language is called ariya, and the Elamite version of the inscription portrays the Zoroastrian deity Ahura Mazdā as the "god of the Aryas" (ura-masda naap harriia-naum).
The self-identifier was inherited in ethnic names such as the Parthian Ary (pl. Aryān), the Middle Persian Ēr (pl. Ēran), or the New Persian Īrāni (pl. Īrāniyān). The Scythian branch has Alān or *Allān (from *Aryāna; modern Allon), Rhoxolāni ('Bright Alans'), Alanorsoi ('White Alans'), and possibly the modern Ossetian Ir (adj. Iron), spelled Irä or Erä in the Digorian dialect. The Rabatak inscription, written in the Bactrian language in the 2nd century CE, likewise uses the term ariao for 'Iranian'.
The name Arizantoi, listed by Greek historian Herodotus as one of the six tribes composing the Iranian Medes, is derived from the Old Iranian *arya-zantu- ('having Aryan lineage'). Herodotus also mentions that the Medes once called themselves Arioi, and Strabo locates the land of Arianē between Persia and India. Other occurrences include the Greek áreion (Damascius), Arianoi (Diodorus Siculus) and arian (pl. arianōn; Sasanian period), as well as the Armenian expression ari (Agathangelos), meaning 'Iranian'.
Until the demise of the Parthian Empire (247 BCE–224 CE), the Iranian identity was essentially defined as cultural and religious. Following conflicts between Manichean universalism and Zoroastrian nationalism during the 3rd century CE, however, traditionalistic and nationalistic movements eventually took the upper hand during the Sasanian period, and the Iranian identity (ērīh) came to assume a definite political value. Among Iranians (ērān), one ethnic group in particular, the Persians, were placed at the centre of the Ērān-šahr ('Kingdom of the Iranians') ruled by the šāhān-šāh ērān ud anērān ('King of Kings of the Iranians and non-Iranians').
Ethical and ethnic meanings may also intertwine, for instance in the use of anēr ('non-Iranian') as a synonymous of 'evil' in anērīh ī hrōmāyīkān ("the evil conduct of the Romans, i.e. Byzantines"), or in the association of ēr ('Iranian') with good birth (hutōhmaktom ēr martōm, 'the best-born Arya man') and the use of ērīh ('Iranianness') to mean 'nobility' against "labor and burdens from poverty" in the 10th-century Dēnkard. The Indian opposition between ārya- ('noble') and dāsá- ('stranger, slave, enemy') is however absent from the Iranian tradition. According to linguist Émile Benveniste, the root *das- may have been used exclusively as a collective name by Iranian peoples: "If the word referred at first to Iranian society, the name by which this enemy people called themselves collectively took on a hostile connotation and became for the Aryas of India the term for an inferior and barbarous people."
Old Persian names derived the stem *arya- include Aryabignes (*arya-bigna, 'Gift of the Aryans'), Ariarathes (*Arya-wratha-, 'having Aryan joy'), Ariobarzanēs (*Ārya-bṛzāna-, 'exalting the Aryans'), Ariaios (*arya-ai-, probably used as a hypocorism of the precedent names), or Ariyāramna (whose meaning remains unclear). The English Alan and the French Alain (from Latin Alanus) may have been introduced by Alan settlers to Western Europe during the first millennium CE.
In ancient Sanskrit literature, the term Āryāvarta (आर्यावर्त, the 'abode of the Aryas') was the name given to the cradle of the Indo-Aryan culture in northern India. The Manusmṛiti locates Āryāvarta in "the tract between the Himalaya and the Vindhya ranges, from the Eastern (Bay of Bengal) to the Western Sea (Arabian Sea)".
The stem airya- also appears in Airyanəm Waēǰō (the 'stretch of the Aryas' or the 'Aryan plain'), which is described in the Avesta as the mythical homeland of the early Iranians, said to have been created as "the first and best of places and habitations" by the god Ahura Mazdā. It was referred to in Manichean Sogdian as ʾryʾn wyžn (Aryān Wēžan), and in Old Persian as *Aryānām Waiǰah, which gave the Middle Persian Ērān-wēž, said to be the region where the first cattle were created and where Zaraθuštra first revealed the Good Religion. The Sasanian Empire, officially named Ērān-šahr ('Kingdom of the Iranians'; from Old Persian *Aryānām Xšaθram), could also be referred to by the abbreviated form Ērān, as distinguished from the Roman West known as Anērān. The western variant Īrān, abbreviated from Īrān-šahr, is at the origin of the English country name Iran.
Alania, the name of the medieval kingdom of the Alans, derives from a dialectal variant of the Old Iranian stem *Aryāna-, which is also linked to the mythical Airyanem Waēǰō. Besides the ala- development, *air-y- may have turned into the stem ir-y- via an i-mutation in modern Ossetian languages, as in the place name Iryston (Ossetia), here attached to the Iranian suffix *-stān.
Other place names mentioned in the Avesta include airyō šayana, a movable term corresponding to the 'territory of the Aryas', airyanąm dahyunąm, the 'lands of the Aryas', Airyō-xšuθa, a mountain in eastern Iran associated with Ǝrəxša, and vīspe aire razuraya, the forest where Kavi Haosravō slew the god Vāyu.
The word Arianus was used to designate Ariana, the area comprising Afghanistan, Iran, North-western India and Pakistan. In 1601, Philemon Holland used 'Arianes' in his translation of the Latin Arianus to designate the inhabitants of Ariana. This was the first use of the form Arian verbatim in the English language.