Historians are still debating when the first inhabitants settled in what is now Iran,but ongoing excavations suggest that during Neolithic times small numbers of hunters lived in caves of Zagros & Alborz mountains.
The first cities known to established was close enough to the great Sumerian civilization.
It was here that the Elamites established their capital at Shush,Fars Province.In the 7th century BC the king of one of the Persian tribes,Achemenes ,managed to create a unified state in southern Iran,what was to become The First Persian Empire.
Achaemenid Empire,set up with its capitals at Shush,Persepolis and Ecbatana(Most of them are issued as UNESCO World Heritage sites),established Zoroastrianism as state religion.
Alexander the Great invaded Persia & sacks Perspolis.Many kings and dynasties came & changed such as Seleucid government,Parthian,Sassanian Empires,Seljuk,Mongol dynasties,Safavids are the next known as one of concentrated & centralized governments by announcing Shiite Islam as state religion,plus profitances in Persian Architecture,Arts & Industry.
Persia in period of Qajars experienced many crisises like wars,famine & diseases devastating large numbers of people.
Iran used to be called Persia,a name derived(like Farsi)from the name of Fars province where the Aryan tribes had settled.In 1934 Reza Shah had the country’s name changed to Iran-derived directly from Aryan(meaning ‘of noble origin’).Finally the circulations of kings ended by Iranian Islamic Revoloution since 40 years ago.