Iran is a Modern Persian derivative from the Proto-Iranian term Āryānam, meaning “land of the Aryans,” first attested in Avesta. The term Ērān is found in a 3rd-century Middle Persian inscription at Naqsh-e Rostam, and the term Āryān is used in the Parthian inscription that accompanies it, in reference to Iranians.
Historically, Iran has been referred to as Persia by the West, due mainly to the writings of Greek historians who called Iran Persis (Περσίς), meaning “land of the Persians.” As the most extensive interactions the Ancient Greeks had with any outsider was with the Persians, the term persisted, even long after the Persian rule in Greece.
In 1935, Reza Shah requested the international community to refer to the country by its native name, Iran. As the New York Times explained at the time, “At the suggestion of the Persian Legation in Berlin, the Tehran government, on the Persian New Year, Nowruz, March 21, 1935, substituted Iran for Persia as the official name of the country.” Opposition to the name change led to the reversal of the decision, and Professor Ehsan Yarshater, editor of Encyclopædia Iranica, propagated a move to use Persia and Iran interchangeably. Today, both Persia and Iran are used in cultural contexts; although, Iran is the name used officially in political contexts.
Historical and cultural usage of the word Iran is not restricted to the modern state proper. Irānzamīn or Irān e Bozorg (Greater Iran) correspond to territories of the Iranian cultural and linguistic zones. In addition to modern Iran, it includes portions of the Caucasus, Mesopotamia, Anatolia, and Central Asia.