More 18th-century Thai history. King Phetracha to the end of the Ayudhya Kingdom.  The ethnic Chinese contribution to building the foundation of the Thai economy is legendary.  Here's where it all began. During this period China, ruled by the Manchu Qing emperors was on a major roll, and Ayudhyan kings were anxious to be friends with Kangxi, Yongzheng, and Qianlong.  Having the Thai-Chinese around came in handy in a very big way.