Historically, the name Armenian has come to internationally designate this group of people. It was first used by neighbouring countries of ancient Armenia. The earliest attestations of the exonymArmenia date around the 6th century BC. In his trilingual Behistun Inscription dated to 517 BC, Darius I the Great of Persia refers to Urashtu (in Babylonian) as Armina (in Old Persian; Armina () and Harminuya (in Elamite).
In Greek, Αρμένιοι "Armenians" is attested from about the same time, perhaps the earliest reference being a fragment attributed to Hecataeus of Miletus (476 BC).Xenophon, a Greek general serving in some of the Persian expeditions, describes many aspects of Armenian village life and hospitality in around 401 BC. He relates that the people spoke a language that to his ear sounded like the language of the Persians.
Armenians call themselves Hay (Armenian: հայ, pronounced [ˈhaj]; plural: հայեր, [haˈjɛɾ]). The name has traditionally been derived from Hayk (Armenian: Հայկ), the legendary patriarch of the Armenians and a great-great-grandson of Noah, who, according to Moses of Chorene, defeated the Babylonian king Bel in 2492 BC and established his nation in the Ararat region. It is also further postulated that the name Hay comes from one of the two confederated, Hittite vassal states—the Ḫayaša-Azzi (1600–1200 BC).
Movses Khorenatsi, the important early medieval Armenian historian, wrote that the word Armenian originated from the name Armenak or Aram (the descendant of Hayk).