The civil war between the Lê-Trịnh and Mạc dynasties led to 1592, when the army of Trịnh Tùng conquered Hanoi and executed king Mạc Mậu Hợp. Survivors in the Mạc royal spouse and children fled towards the northern mountains within the province of Cao Bằng and ongoing to rule there https://gk8887642.blue-blogs.com/37982426/6623-for-dummies