The Kushan empire, acknowledged by contemporaries as one of the four great Eurasian powers of its time (the others being China, Rome, and Parthia), declines after the rise of the Sassanian dynasty in Iran and of local powers in northern India.

Although the empire fragments into petty principalities, Kushan princes long continue their rule in various provinces.

Under the second Sassanian ruler, Shapur I, the Persians establish control over parts of Afghanistan, including Bagram, in 241.

Variations on the word “Afghan”may date from as early as a third-century Sassanian reference to “Abgan”.