The Achaemenids were overthrown by the conquest of Alexander the Great in 330 BC.



The Parthian Empire (238 BC - 226 AD) was the third Iranian kingdom to dominate Greater Iran in ancient times. Parthia itself was located south-east of the Caspian Sea, between the Kopet Dag mountains and the Dasht-e-Kavir desert.[1] The empire was ruled by the Arsacid Dynasty, and at its height they controlled most of Armenia, Mesapotamia, Iran, and Afghanistan.


The Parthians were consummate horsemen, known for a military tactic called the Parthian shot. They are noted in western history for defeating the Greek Seleucid Empire and ending the Hellenization of Iran. The Empire also became a rival state of the powerful Roman Empire.



The Sassanid Empire or Sassanian Dynasty (Persian: ساسانیان [sɒsɒnijɒn]) is the name used for the third Iranian dynasty and the second Persian Empire (226--651).[3] The Sassanid dynasty was founded by Ardashir I after defeating the last Parthian (Arsacid) king, Artabanus IV (Persian: اردوان Ardavan) and ended when the last Sassanid Shahanshah (King of Kings), Yazdegerd III (632--651), lost a 14-year struggle to drive out the early Arab Caliphate, the first of the Islamic empires. The Sassanid Empire's traditional territory encompassed all of today's Iran, Iraq, Armenia, Afghanistan, eastern parts of Turkey, and parts of Syria, Pakistan, Caucasia, Central Asia and Arabia. The Sassanids called their empire Eranshahr "Dominion of the Iranians (Aryans)".


Relation between persian empire and chinese empire: