Many scholarly works on the Silk Roads stop with the arrival of Islam and the decline of the Buddhist culture of Xinjiang. Merchants, however, continued to trade in the many commodities of Central and East Asia. The eastern Islamic states of the 10th–11th centuries took a keen interest in this commerce. Their rulers treasured exotic goods, and they encouraged trade because of the value of commerce to their own standing as patrons within their lands. Valuable textiles and other treasures formed the diplomatic and political currency of the realms. Thus the new powers of the eastern Islamic world continued the ancient overland trade through Eurasia.