Because Mac dynasty loyalists were revolting in "Thuan Hoa" and Trinh Kiem was busy fighting the Mac dynasty forces in northern Vietnam during this time, Ngoc Bao's request was approved and Nguyen Hoang went south. After Hoàng pacified Thuan Hoa, he and his heir Nguyen Phuc Nguyen serectly made this region loyal to the Nguyen family; then they rose against the Trinh Lords. Vietnam erupted into a new civil war between two "de facto" ruling families: the clan of the Nguyen lords and the clan of the Trinh lords.