In 1407, around 9,000 Viet elitists, including scholars, craftmen, physicians, medicine experts were shipped to China proper, where these people were retrained in Chinese and could be sent back to Jiaozhi as bureaucrats.
[4] In 1420, Lê Ngã rallied people to the woods of Lạng Sơn and subsequently declared king.
The Ming military commander of Jiaozhi–Marquis Li Bin, arrived and forced Lê Ngã's rebels to flee into the mountains.
[1] After hearing the news, the Yongle Emperor felt angry and demanded that Lê Ngã be captured and transported to the Ming capital.
Unable to immediately have the emperor's demand succeed, Li Bin seized and sent an innocent man instead, claiming that it was Lê Ngã.