 This was caused by a change of policy by the Song dynasty to no longer accept ambassadors from Srivijaya and Jambi's inability to cope with changing scenario.Instead of the Jambi controlling the trade through tributary system, traders were allowed to trade directly.According to George Coedes, by the beginning of the fourteenth century, Melayu "remained the only Sumatranese state of some political importance and it had become the refuge of Indian culture in opposition to the sultanates of the north that were already Islamized or in the process of becoming so."