Ming campaigns against Annam, 1381-1388 (start of the fourth period of northern rule)

Timeline

1. 1381Yongping Stockade · Siming PrefectureIn Hongwu 14, troops from Annam's Tuo and Dong counties attacked Yongping and other stockades of Siming Prefecture in Guangxi. Siming's native official Huang Hudu reported, and Annam's envoys counter-accused Siming of raiding its counties. The Ming founder ruled that Annam 'committed evil and insult, sowing discord and trouble,' and sent envoys to reprimand; Annam admitted the incursions but refused to fully return the occupied land.
2. 1385–1387Thang Long (Annam's capital) · Red River DeltaTran Thuong Due wared with Champa for over a decade and repeatedly invaded Siming's territory; chancellor Le Quy Ly gradually took real power. The Ming sent envoy Lu Rang with a letter accusing him of regicide and disordering the state, then ordered Chen Cheng and Lu Rang into Annam to demand the return of five seized counties including Khu Van and Khanh Vien. Le Quy Ly, acting in King Tran Nhan Tong's name, used both soft and hard tactics, refused to return them, and memorialized the Ministry of Rites to argue, keeping Sino-Vietnamese relations tense.
3. 1388Yingtian (Nanjing) · Yingtian PrefectureIn Hongwu 21, Le Quy Ly deposed and killed Annam's king Tran Due (the Deposed Emperor Tran), installed a young ruler, and carried out a large-scale purge of the Tran clan. Though the Ming court knew of the regicide, it adhered to its non-invasion policy and responded only by rejecting tribute and refusing envoys, effectively rupturing the vassal relationship and paving the way for later tribute cutoffs and the Yongle southern campaign.