Aftermath of the Fall of the Sasanian Empire

Timeline

1. 651–660Khorasan · IranThe last Sasanian king Yazdegerd III fled east to Khorasan under Arab pursuit and was killed by a local miller, formally ending the four-century Sasanian dynasty; after the collapse of central authority, provincial governors and military nobles each went their own way, and Iran fell into fragmentation.
2. 650–680Isfahan and Fars · IranZoroastrian priests and old Persian nobles organized resistance in Isfahan, Fars, and elsewhere, with some local warlords claiming to continue Sasanian legitimacy; although Arab forces occupied the major cities, their control of the Iranian plateau's mountainous regions remained insecure, and the conquest process continued for decades.
3. 680–700Kufa and the Iranian governorate · Western AsiaAfter the Umayyad dynasty was established, it implemented the diwan administrative system in Iran, retaining large numbers of Persian secretaries and tax collectors, with Persian becoming one of the empire's administrative languages; Zoroastrianism gradually declined while Islam coexisted with Christian and Jewish communities, and Persian literary, artistic, and architectural traditions merged into Islamic culture, laying the groundwork for the 'Persianization of Islam' before and after the Abbasid Revolution.