Hong-wu: Year 21, Month 12, Day 13
10 Jan 1389
The minister Ruan Wan and others who had been sent by Annam, came to present a memorial of gratitude for the Imperial orders and patterned fine silks which had been conferred, and offered tribute of four elephants and three elephant handlers. The Emperor, noting that their coming to Court was too frequent, that the goods they offered were often greatly extravagant and that the trip was arduous, commanded the Ministry of Rites to send a despatch to the country of Annam requiring it to come to Court once every three years. As to tribute, they were only to offer their own products and only one person was permitted to present them. The offering of tribute was to be an indication of loyalty and respect, no more. No elephants or rhinoceros products were to be again given as these caused the people much trouble.
Zhong-yang Yan-jiu yuan Ming Shi-lu, volume 7, page 2917/18