Central Asia came under Arab control after a series of invasions in the late 7th and early 8th centuries and was incorporated into Islamic Caliphate divided between provinces of "Mawara'un Nahr" and Khorasan. The Arab conquest brought the religion of Islam to all of the peoples of central Asia. The city of Merv was occupied by the lieutenants of the caliph Uthman ibn Affan, and was constituted as the capital of Khorasan. Using this city as their base, the Arabs, led by their commander Qutayba ibn Muslim, brought under subjection Balkh, Bokhara, Fergana and Kashgaria, and penetrated into China as far as the province of Kan-suh early in the 8th century.