The history of Iran started properly by the Mede at least the eight-century B.C they were Indo-Europeans. Cyrus the Great established new empire in 550 B.C , made Pasargade , Babylonia , Ecbatana , as his capitals. He offered freedom to Jews captured in Babylonia and ordered to rebuild their Temple. The dynasty of Cyrus and Darius was called Achaemenid. They were defeated in 331-30 B.C by Alexander , who burnt Persepolis , married with the daughter of Darius III , and died few years later. His vast empire was divided between his generals , Greek settlement in Iran was soon challenged by the Arsacide Parthians , an Iranian people from north -east in 238.B.C.During 500 years of power , the parthians had to face with Romans-the Sagas-from Chinese and Turkmenistan in the east. At this time Pahlavi became the official language of the empire.

The Sassanid dynasty started in 224.A.D. The empire of Sassanid paid attention to develop the towns , irrigation and industrialization. The Romans were conquered in A.D.242 , the area controlling by the Sassanid stretching from Euphrates to Merv and the Punjab , including Heart and Sis-tan. Unfortunately this powerful dynasty succumbed to the invasion of Arabs in 637 A.D Iran changed the Zoroastrian religion to Islam. The control of the Empire fell into the hands of Arab caliphs for more than 500 years , but inside the country especially in the north ( Caspian sea ) there were some local independent governments such as Buyides , or Ghaznavids , between A.D. 1040 and 1055 , both were defeated by Seljuk , a Turkish-speaking people of Irano-turkish clan established Turkistan , They founded a vast empire that came to an end with the Mongol invasion under Chengis khan in A.D.1218.Second Mongol invasion under Hulaku destroyed the powerful Caliphate of Baghdad and Assassin sect ( Ishmaelite sect ) in A.D.1256.

These Mongols had done such destruction to the country that many cities were totally wiped from the face of the earth. In fourteenth century , Tamer-lane , another conqueror from central Asia , put an end Mongol rule and established timurid dynasty in Iran under which for a time literature and the arts were flourished. For a short time , the Turkmen Qaraqoyunlu came to the power that in fifteenth century were followed by the ottomans? Turk , this resoled in confusion and rivalry that finally came over with arrival of Safavid.

In 1501 , Shah Abbas who was in power consolidated his kingdom suppressing rebellions and built many roads and monuments , caravanserais , etc. After shah Abbess's death , the country once again was the scene of a series of wars , with the Uzbeks Afghans , Russia , and turkey's. this dynasty disappeared at 1747 , the zand dynasty followed ruling the country for a short time , but with the crew  assassination of the lotfali khan zand by Mohammad Qadjar , the dynasty of Qadjar started their ruling over country till 1925.

 The only positive point of their ruling was the establishment of a House of Parliament. The last king of Qadjar , Ahmad Shah , formally deposed and Reza Khan , a commander of Persian Cossack brigade by a coup became king and founded the Pahlavi dynasty that came to an end by Islamic Revolution in 1979.From this time , Iran changed the monarchy system to an Islamic republic system.