Reason of Khorasan Conquest: Sassanid Ruler III, who withdrew to Merv in eastern Iran. Not allowing Yazdcerd to recover.
Result of Khorasan Conquest: Khorasan was captured, so the borders were expanded up to the Ceyhun river.
CONQUEST OF HORASAN BRIEF SUMMARY
Sassanid Ruler III, who withdrew to Merv in eastern Iran. Khorasan was captured as a result of the expedition made to prevent Yazdcerd’s recovery and to conquer the region, thus expanding the borders up to the Ceyhun river.
The rapid expansion of the borders of the Islamic State and the increase in the population caused some problems in administration. Hz. Since many conquests were made in the time of Omar (ra), the need for organization in the state increased. Sassanid and Byzantine influence is seen in the organization.