Mạc dynasty
Because Mạc dynasty loyalists were revolting in Thuận Hóa and Trịnh Kiểm was busy fighting the Mạc dynasty forces in northern Vietnam during this time, Ngoc Bao's request was approved and Nguyễn Hoàng went south. After Hoàng pacified Thuận Hóa, he and his heir Nguyễn Phúc Nguyên serectly made this region loyal to the Nguyễn family; then they rose against the Trịnh Lords. Vietnam erupted into a new civil war between two "de facto" ruling families: the clan of the Nguyễn lords and the clan of the Trịnh lords.