The Samanid Empire was the first native Persian dynasty to arise after the Muslim Arab conquest. The four grandsons of the dynasty's founder, Saman Khuda, had been rewarded with provinces for their faithful service to the Abbasid caliph al-Mamun: Nuh obtained Samarkand; Ahmad, Fergana; Yahya, Shash; and Elyas, Herat. Ahmad's son Nasr became governor of Transoxania in 875, but it was his brother and successor, Ismail Samani who overthrew the Saffarids and the Zaydites of Tabaristan, thus establishing a semiautonomous rule over Transoxania and Khorasan, with Bukhara as his capital.