Vietnam–Chiem War (1367–1396)
The Vietnam–Chiem War (1367–1396) was a war between Dai Viet in the late Tran dynasty and Champa Kingdom led by Che Bong Nga (1360–1390). In the 1330s, Dai Viet and the Khmer Empire became weakened by climate change and widespread famine, contributing to the revival of Champa in the 14th century. In 1360, Che Bong Nga came to power and asked the Tran Dynasty to return some of the previously offered land. From the 1360s, Champa began a series of continuous wars that lasted nearly three decades with Dai Viet and was won many times. Thang Long Citadel many times fell into the hands of the Champa people during the war. In 1377, Tran Due Tong organized a counterattack and advanced as far as Do Ban citadel, but was eventually ambushed outside the city and died. In 1390, Che Bong Nga was killed in a naval battle with the help of a defected general Chiem.
A decisive factor in the Dai Viet army's victory in the Battle of Hai Trieu was its deadly gunpowder and firearms, which caused Che Bong Nga to be killed in 1390. At the end of the war, both sides had exhausted their human resources and material resources, achieving little while suffering great losses. The Tran Dynasty lost power to Ho Quy Ly in 1400.
The cause of the conflict began after the successful resistance war against the Mongols in the 13th century. The alliance against the Nguyen Dynasty brought Dai Viet and Champa, which were hostile, closer together. In 1306, the Tran Dynasty married Princess Huyen Tran to King Che Man of Champa. Che Man ceded two continents O and Ly to Dai Viet as a wedding gift. The Tran Dynasty renamed these two lands to Hoa Chau and Thuan Chau. In 1307, Che Man died, the Tran family feared that Princess Huyen Tran would be burned to be cremated. King Tran Anh Tong sent Tran Khac Chung to borrow his voice to visit and use the scheme to bring Huyen Tran back to the country. However, some later people thought that this story was somewhat fabricated, saying that the princess's need to go to the pyre was just "a deliberate rumor of characters who disagreed with the Tran Dynasty and opposed the pyre." with heterosexual marriages, emerging Confucians". Besides the dubious contrasts and unreasonable points in the history books, the historical records of Champa and all the ancient books on the cremation ceremony do not mention this custom of the Champa people, which is unlikely to be true. The death of the Cham king in 1307 caused many Cham people to demand the return of their offered territories. In 1311–1312, Tran Anh Tong brought his army to fight Champa, captured Che Chi, and replaced his brother Che Nang as a vassal of the Tran dynasty. Che Chi soon died in Gia Lam and was cremated. Che Nang later revolted, but was defeated in 1318, forced to flee to Java and was replaced by Che Anan. After the Tran army withdrew, Che Anan increased tribute to the Nguyen Dynasty, and at the same time persuaded the Nguyen king to support Chiem in gaining autonomy from Dai Viet. In 1324, Nguyen Anh Tong sent an envoy to entice Tran Minh Tong to respect the sovereignty of Champa. In 1326, Tran Minh Tong sent King Hue Tuc to Tran