The extraordinary ascendancy of the Saffarid dynasty began with the meteoric career of its founder, Yaʿqūb b. al-Layth al-Saffār. Yaʿqūb appeared on the historical scene in 238/852 as the member of an Eastern Iranian military band, and ended his days as the ruler over a vast swathe of territory stretching from today's ʿIraq to the borders of today's India; while at least theoretical acknowledgement of his overlordship was found both in Central Asia and the holy cities of Arabia.