the reign of the weak king Trần Dụ Tông (r. 1341–1369), internal rebellions led by serfs and peasants from the 1340s and 1360s weakened the royal power. In 1369, due to Trần Dụ Tông's lack of an heir to success, Dương Nhật Lễ, a man from the Dương clan, seized power. A short bloody civil war led by the royal Tran family against the Dương clan broke out in 1369–1370 that created turmoil. The Trần reclaimed the crown, enthroning Trần Nghệ Tông (r. 1370–1372) while Dương Nhật Lễ was deposed and executed. Duong's queen mother went into exile in Champa and begged Cham king Po Binasuor to help her get revenge. Took advantage, Champa Empire under Po Binasuor (Chế Bồng Nga) invaded Đại Việt and ransacked Thăng Long in 1371. Six years later, the Đại Việt army suffered a great defeat at Battle of Vijaya, and Trần Duệ Tông (r. 1373–1377) was killed. The Chams then continued to advance north, besieging, pillaging, and looting Hanoi four times, from 1378 to 1383. War with Champa ended in 1390 after the Cham king Che Bong Nga was killed during his northward offensive by Vietnamese forces led by prince Trần Khát Chân, who used firearms in battle. Ming conquest and occupation Hồ Quý Ly (1336–1407)-the minister of the Trần court who has desperately fought off the Cham invasions, now became the most powerful figure in the kingdom. He conducted a series of reforms, including replacing copper coins with banknotes, despite the kingdom still recovering after the devastating war. Time by time, he slowly eliminated the Trần dynasty and aristocracy. In 1400 he deposed the last Trần Emperor and became ruler of Đại Việt. Hồ Quý Ly became emperor, moved the capital to Tây Đô and briefly changed the kingdom's name to Đại Ngu (Great Joy/Peace) (大虞). In 1401 he stepped down and established his second son Hồ Hán Thương (r. 1401–1407) who had Trần blood as king. In 1406, Emperor Yongle of the Ming dynasty, in the name of restoring the Trần dynasty, invaded Đại Ngu. The ill-prepared Vietnamese resistance of Hồ Quý Ly, who failed to get support from his people, especially from the Thăng Long literati, was crumbled and defeated by a Chinese army of 215,000, armed with the newest technology at the time. Đại Ngu kingdom became the thirteenth province of the Ming empire. The short-lived Ming colonial rule had