Greater Iran

Greater Iran or Greater Persia (Persian: ایران بزرگ Irān-e Bozorg), also called the Iranosphere or the Persosphere or Iranzamin (Persian: ایران‌زمین Irān-zamin), is a term used to refer to a broader cultural sphere that has been influenced by Iranian peoples and Iranian languages, and primarily includes the Iranian plateau, the South Caucasus, Central Asia, the Indian subcontinent, and historically stretched as far east as the Tarim Basin.

The regions which make up Greater Iran are defined by having long been under the rule of various Iranian empires and dynasties, during which the local populace gradually absorbed Iranian influence and assimilated it into their cultural and linguistic traditions; or those where a considerable Iranian population settled and retained their culture, such as in the areas surrounding the Iranian plateau. It is referred to as the "Iranian Cultural Continent" by Encyclopædia Iranica.

Many of the regions that were once part of Greater Iran were lost in conflicts to other powers. Throughout the 16th to 19th centuries, Iran lost many of its historical territories that had been reconquered under the Iranian dynasties of the Safavids and Qajars. The Ottoman–Persian 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-Persian 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 of Iran 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.