Greater Iran

Greater Iran or Greater Persia (Persian: ایران بزرگ Irān-e Bozorg), also called the Iranosphere or the Persosphere, is an expression that denotes a wide socio-cultural region comprising parts of West Asia, the South Caucasus, Central Asia, South Asia, and East Asia (specifically the Tarim Basin)—all of which have been affected, to some degree, by the Iranian peoples and the Iranian languages.

It is defined by having long been ruled by the dynasties of various Iranian empires, under whom the local populaces gradually incorporated some degree of Iranian influence into their cultural and/or linguistic traditions; or alternatively as where a considerable number of Iranians settled to still maintain communities who patronize their respective cultures, geographically corresponding to the areas surrounding the Iranian plateau. It is referred to as the "Iranian Cultural Continent" by Encyclopædia Iranica.

Throughout the 16th–19th centuries, Iran lost many of the territories that had been conquered under the Safavids and Qajars.

The Ottoman–Iranian Wars resulted in the loss of present-day Iraq to the Ottoman Empire, as outlined in the Treaty of Amasya in 1555 and the Treaty of Zuhab in 1639.

Simultaneously, the Russo-Iranian Wars resulted in the loss of the Caucasus to the Russian Empire: the Treaty of Gulistan in 1813 saw Iran cede present-day Dagestan, Georgia, and most of Azerbaijan; the Treaty of Turkmenchay in 1828 saw Iran cede present-day Armenia, the remainder of Azerbaijan, and Iğdır, setting the northern boundary along the Aras River.

Parts of Afghanistan were lost to the British Empire through the Treaty of Paris in 1857 and the McMahon Arbitration in 1905.

The name "Iran", meaning "land of the Aryans", is the New Persian continuation of the old genitive plural aryānām (proto-Iranian, meaning "of the Aryans"), first attested in the Avesta as airyānąm (the text of which is composed in Avestan, an old Iranian language spoken in northeastern Greater Iran, or in what are now Afghanistan, Uzbekistan, Turkmenistan and Tajikistan).

The proto-Iranian term aryānām is present in the term Airyana Vaēǰah, the homeland of Zoroaster and Zoroastrianism, near the provinces of Sogdiana, Margiana, Bactria, etc., listed in the first chapter of the Vidēvdād. The Avestan evidence is confirmed by Greek sources: Arianē is spoken of as being between Persia and the Indian subcontinent.