(Excepts from our pages Who Were the Aryans? Post Classical Western Authors and Western Views.)
Who Were the Aryans?
The Indo-Iranian group whose members composed the Zoroastrian scriptures, the Avesta and the oldest of the Hindu Scriptures, the Rig Veda, called themselves Aryans (Airya/Airyan in the Avesta and Arya/Aryan in the Vedas). The name Arya or Aryan was used in the same manner as we would use Iranian today. Iran is the modern version of Airan (from Airyana, land of the Airya/Aryans).
In the same manner that there are Iranian-like people who are not Iranian, and non-Iranian-like people who are Iranian, the same would have held true for the greater ancient Aryan nation (cf. the sixteen nations listed in the Avesta's Book of Vendidad, or the core nations of the Bactrian, Median, Achaemenian Persian, Parthian, and Sassanian empires. Arya/Aryan is the name of a community, a society, a nation as well as the people of that nation).
Earliest References to the Aryans
The only known ancient texts that contain references to Aryans are the Zoroastrian scriptures, the Avesta and the Hindu Scriptures, the Vedas.
The next references are in the inscriptions of the Achaemenian Persians (see Achaemenian History as well as our page on Naqsh-e Rustam).
Earliest Surviving Western References to the Aryans
Classical Greek texts such as those of Herodotus and Strabo, mention the Aryans exclusively with respect to the Central Asian ancestry of the Medes and Persians. Strabo called the old lands of the Aryans, Ariana or Aryana (cf. Airyana of the Avesta).
How the Aryans Entered Modern Western Consciousness
Anquetil du Perron (1731-1805)
Frenchman Anquetil du Perron was the first Western scholar who travelled to India in order to obtain Avesta manuscripts. He then attempted an early translation of the texts he had obtained into French, and published his translation in three volumes under the title Le Zend-Avesta, ouvrage de Zoroastre.