Quanzhou initially continued to thrive under the Southern Song produced by the Jin–Song Wars. A 1206 report listed merchants from Arabia, Iran, the Indian subcontinent, Sumatra, Cambodia, Brunei, Java, Champa, Burma, Anatolia, Korea, Japan and the city-states of the Philippines. One of its customs inspectors, Zhao Rugua, completed his compendious "Description of Barbarian Nations" , recording the people, places, and items involved in China's foreign trade in his age. Other imperial records from the time use it as the zero mile for distances between China and foreign countries. Tamil merchants carved idols of Vishnu and Shiva and constructed Hindu temples in Quanzhou. Over the course of the 13th century, however, Quanzhou's prosperity declined due to instability among its trading partners and increasing restrictions introduced by the Song in an attempt to restrict the outflow of copper and bronze currency from areas forced to use hyperinflating paper money. The increasing importance of Japan to China's foreign trade also benefited Ningbonese merchants at Quanzhou's expense, given their extensive contacts with Japan's major ports on Hakata Bay on Kyushu.