Parthian Empire and Sasanian Empire

The Parthian Empire, also known as the Arsacid Empire, was a major Iranian political and cultural power centered in ancient Iran from 247 BC to 224 AD. Its latter name comes from its founder, Arsaces I, who led the Parni tribe in conquering the region of Parthia in Iran's northeast, then a satrapy (province) under Andragoras, who was rebelling against the Seleucid Empire. Mithridates I (r. c. 171 – 132 BC) greatly expanded the empire by seizing Media and Mesopotamia from the Seleucids. At its height, the Parthian Empire stretched from the northern reaches of the Euphrates, in what is now central-eastern Turkey, to present-day Afghanistan and western Pakistan. The empire, located on the Silk Road trade route between the Roman Empire in the Mediterranean Basin and the Han dynasty of China, became a center of trade and commerce.

The Sasanian Empire, officially Eranshahr (Middle Persian: 𐭠𐭩𐭥𐭠𐭭𐭱𐭲𐭥𐭩, romanized: Ērānšahr, lit. 'Empire of the Iranians'), was an Iranian empire that was founded and ruled by the House of Sasan from 224 to 651 AD (the era of late antiquity). Lasting for over four centuries, the length of the Sasanian dynasty's reign over ancient Iran was second only to that of the Arsacid dynasty of Parthia which immediately preceded it.