The Sasanian Empire of the Iranians lasted from 224 to 651
Ardashir I founded Eranshahr after Parthia's collapse, claiming Achaemenid restoration. For over four centuries the House of Sasan ruled from Ctesiphon across Iran, Iraq, and far fringes—until Byzantine war and Arab conquest ended the last pre-Islamic Iranian empire.
Officially titled the Empire of the Iranians in Middle Persian, this late antique state was created by Sasan's descendants and endured more than four centuries, from the year 224 until 651. Ardashir I rose as Arsacid power frayed under internal and external stress, determined to expand Iranian dominion in the spirit of earlier Achaemenid greatness. At its height the state held all of modern Iran and Iraq, stretches of the Arabian Peninsula including eastern and southern coasts, the Caucasus, the Levant, and parts of Central Asia and the Indian subcontinent, keeping Ctesiphon as capital as under the Parthians.
Scholars treat the era as a high point of Iranian civilization: centralized bureaucracy, revived Zoroastrianism as unifying ideology, grand monuments and public works, and patronage of culture and learning. The Great Inscription of Shapur I first attests the imperial self-name when the king calls himself lord of the Empire of the Iranians. English also uses Sassanian, Sasanid, or Sassanid, all pointing back to the eponym Sasan. Conflicting narratives obscure how Parthia fell; tradition places the new empire's establishment at Estakhr.
After Islam rose in Arabia and a ruinous war with Byzantium drained the treasury and armies, early Muslim conquests begun under Muhammad and continued by the Rashidun Caliphate toppled the Sasanians. The Muslim conquest of Iran marked deep religious and cultural change, yet Sasanian administrative and artistic habits still shaped successor courts. Four centuries of imperial identity thus ended not with a quiet fade but with military collapse after fighting Rome one war too many.
Source: Sasanian Empire
