In 1400 Vietnamese leader and radical reformer Hồ Quý Ly (ca. 1350–1410) usurped the Vietnamese throne from the declining Trần leadership. Hồ Quý Ly’s reign, although fueled by regional rivalries, managed to provoke a military response by the neighboring Ming that displaced the dominant Đông Kinh elite of the Red River Delta long enough for the Thanh Hóa elite of upper central Vietnam under Lê Lợi (1385–1433) to unify a political force that would borrow heavily from the Chinese model, but stress essential cultural differences between the two sides of the Sino-Vietnamese frontier. The Ming occupation of Vietnam would last only two decades, but this period continues to have an influence on the modern-day relationship between the People's Republic of China and the Socialist Republic of Vietnam. This chapter draws connections between Hồ Quý Ly’s radical reforms, the failed Ming response, and Sino-Vietnamese relations today.